I think it's most likely, as the article suggests, that this is simply a mistake. With Arm machines going to be announced in 2 or 3 weeks, unlikely that they squeeze a new 16" intel machine out in the narrow time that's left in the year.
If Apple is trying to get a Macintosh onto the Thunderbolt v4 rollout train then the MBP 16" would make sense to go first.
Thunderbolt has not been tightly coupled to A-series SoCs. It is not particularly likely that Apple would choose 2-3 years ago to couple their firsts "Apple Silicon Mac" to Thunderbolt 4. There is a more than decent chance it will be missing from the first Apple Silicon (ASi) Mac. ( even TBv3 might be missing from the first Apple Silicon Mac if this starts off with the re-birth on the one-port-wonder MacBook system class. ) . If Apple is kneecapping the first ASi Mac out the door on port I/O it would help clarlify long term plans greately to have the "opposite" leaning system go out along side it. (That would help them get out the message the "we are going to do the ports better later on across all of the systems " )
If Apple coupled the system to TBv4 then would be waiting on Gen 11 H ( Tiger Lake H) which is every end of 2020 coupled. There really isn't much of another path to roll out a system like that. ( without redo other MBP 13" macs done earlier in 2020. That wouldn't make sense. )
The MBP 16" isn't a top volume seller. So little rhyme or reason to doing that one first. If it is not being replaced soon then an Intel replacement helps Apple 'kick the can' into mid-late 2021 on the MBP 16". Maybe not what some folks want to hear but it makes sense. Even more sense if this first iteration ASi doesn't have a integrated GPU than can top a AMD Radeon Pro 5600M with HBM v2 in both computation throughput and 3D graphics primatives.
Apple has something that plays in the iGPU space. The discrete GPU space they don't. That is not permanent, but it also isn't likely "first generation" offering either.
So if the first ASi Mac laptop and a Gen 11 MBP 16" are priced approximately $1,000 apart from each other the likelihood that folks would get them confused as "substitutable goods" is extremely low. As has been par-for-the-course for the last more than several years, Apple has more than a couple parts of its Mac line up that have gone "stale". It is going to be ways easier for Apple to plug some of that with Intel offerings. It is probably not going to be a short , "Big Bang" transition.