Macs have three model numbers - a number in the format of A plus four digits (which changes the least), plus a number that begins with an M and ends with LL/A and an EMC number. I did a little looking at A number patterns on EveryMac.com today after the new numbers were revealed...
A new "A number", like the 7 (!!!) just uncovered, is generally a significant model change (in the case of a Mac - cellular chips complicate the picture tremendously for things that contain them). That's not always the case - the 2019 iMac processor bump oddly doesn't share an A number with the 2017 of the same screen size. There was also an A number change in the Touch Bar MBPs between the 2017 and 2018 models - but that one corresponds to the addition of the T2.
The new numbers are A2141, A2147, A2158, A2159, A2179, A2182, and A2251. Right now, there are only two Macs with A numbers over A2000 - the new iMacs are A2115 (27") and A2116 (21.5"). There are also a bunch of iPhones and iPads plus the new iPod Touch with numbers over A2000.
How sure are we that "portable personal computer" is a description Apple would only use for a Mac? There actually aren't enough numbers here to be September's iPhones (regional variations of iPhones use up a huge number of A numbers - the 2018 models alone use 12 numbers (four regions and three models in each region). Some of them could be iPads, though (a single iPad uses up four A numbers - the WiFi model, plus three different cellular variations).
As of right now, here are the model numbers of all current portable Macs:
A1466= non-Retina MBA (everything back to 2012 shares an A number, although they have different M and EMC numbers )
A1932= Retina MBA (no variations)
A1534= MacBook (all of the current models - any MacBook with a different A number is one of the old polycarbonate ones from 2010 or earlier)
A1708= 13" non touch bar MBP (back to 2016 - doesn't share an A number with 2015 and prior models)
A1989= 13" Touch Bar MBP (2018 and 2019 models)
A1990= 15" Touch Bar MBP (2018 and 2019 models)
The 2016 and 2017 13" and 15" Touch Bar MBPs have a different A number from the 2018 and 2019 models (A1706 is 13", A1707 is 15"), so a new A number isn't always an obvious redesign - this is probably the T2.
The last two generations of MacBook Pros follow a pattern that the 15" is one number higher than the 13", but this wasn't reliably true prior to 2015. There is a pair in the new list that could be redesigned 13" and 15" (14" and 16"?) models.
Given the information I've found, I think there are three possibilities.
1.) Seven Macs - this seems unlikely! One of them is the redesigned 12" MacBook and two are MBP redesigns, but what are the rest of them? Even assuming that the redesigns of the 13" and 15" each come in two variations significant enough to have separate numbers (OLED and LCD? Neither CPU nor GPU variants have different numbers - even the discrete and integrated graphics 15" models shared an A number), there are still two unexplained Macs. A larger MacBook might use up one of the two, but there have been NO rumors at all relating to the last model. It's not an MBA redesign, because the Retina model is only a few months old.
2.)An iPad using up four numbers, plus three Macs. This fits - they would probably be the 12" MacBook and two MBPs.
3.) A Mac using up four numbers, plus three more Macs. This would require something, presumably the 12" MacBook, to sprout a cellular modem (often requested - it would generate WiFi only plus 3 regional cell variants), plus the two MBPs, plus one more Mac. The two logical possibilities for the "extra" Mac are either a larger (14"?) MacBook (which wouldn't have a cellular variant - it's only one number - or the 14" does, but the 12" doesn't) OR an ultra-high end variant on the 16" MBP. An OLED version could have its own A number...
A new "A number", like the 7 (!!!) just uncovered, is generally a significant model change (in the case of a Mac - cellular chips complicate the picture tremendously for things that contain them). That's not always the case - the 2019 iMac processor bump oddly doesn't share an A number with the 2017 of the same screen size. There was also an A number change in the Touch Bar MBPs between the 2017 and 2018 models - but that one corresponds to the addition of the T2.
The new numbers are A2141, A2147, A2158, A2159, A2179, A2182, and A2251. Right now, there are only two Macs with A numbers over A2000 - the new iMacs are A2115 (27") and A2116 (21.5"). There are also a bunch of iPhones and iPads plus the new iPod Touch with numbers over A2000.
How sure are we that "portable personal computer" is a description Apple would only use for a Mac? There actually aren't enough numbers here to be September's iPhones (regional variations of iPhones use up a huge number of A numbers - the 2018 models alone use 12 numbers (four regions and three models in each region). Some of them could be iPads, though (a single iPad uses up four A numbers - the WiFi model, plus three different cellular variations).
As of right now, here are the model numbers of all current portable Macs:
A1466= non-Retina MBA (everything back to 2012 shares an A number, although they have different M and EMC numbers )
A1932= Retina MBA (no variations)
A1534= MacBook (all of the current models - any MacBook with a different A number is one of the old polycarbonate ones from 2010 or earlier)
A1708= 13" non touch bar MBP (back to 2016 - doesn't share an A number with 2015 and prior models)
A1989= 13" Touch Bar MBP (2018 and 2019 models)
A1990= 15" Touch Bar MBP (2018 and 2019 models)
The 2016 and 2017 13" and 15" Touch Bar MBPs have a different A number from the 2018 and 2019 models (A1706 is 13", A1707 is 15"), so a new A number isn't always an obvious redesign - this is probably the T2.
The last two generations of MacBook Pros follow a pattern that the 15" is one number higher than the 13", but this wasn't reliably true prior to 2015. There is a pair in the new list that could be redesigned 13" and 15" (14" and 16"?) models.
Given the information I've found, I think there are three possibilities.
1.) Seven Macs - this seems unlikely! One of them is the redesigned 12" MacBook and two are MBP redesigns, but what are the rest of them? Even assuming that the redesigns of the 13" and 15" each come in two variations significant enough to have separate numbers (OLED and LCD? Neither CPU nor GPU variants have different numbers - even the discrete and integrated graphics 15" models shared an A number), there are still two unexplained Macs. A larger MacBook might use up one of the two, but there have been NO rumors at all relating to the last model. It's not an MBA redesign, because the Retina model is only a few months old.
2.)An iPad using up four numbers, plus three Macs. This fits - they would probably be the 12" MacBook and two MBPs.
3.) A Mac using up four numbers, plus three more Macs. This would require something, presumably the 12" MacBook, to sprout a cellular modem (often requested - it would generate WiFi only plus 3 regional cell variants), plus the two MBPs, plus one more Mac. The two logical possibilities for the "extra" Mac are either a larger (14"?) MacBook (which wouldn't have a cellular variant - it's only one number - or the 14" does, but the 12" doesn't) OR an ultra-high end variant on the 16" MBP. An OLED version could have its own A number...
