At least October or not at all are not the only options. Remember in 2014, when Apple updated the MacBook Pro at the end of July? ...
Come on, this is getting so silly. Let's look at which months MBP's have been launched from the start:
January x2
February x3
March x2
April x2
May
June x5
July
October x7
November x2
It's pretty clear at least to me that Apple does prefer to do launches in October, or around the (supposedly non-hardware) WWDC. Or somewhere around February. But also not a strict rule. They do refreshes at other times when there's a reason to do so. There are also a few months they generally avoid, for somewhat obvious reasons. May and July (with one exception each), August, September and December.
But the logic you're using, that it's impossible for Apple to do updates in a month if they haven't done so before, do you not see that it's flawed? Before they updated in July the first time, they had never done it. So shouldn't it have been impossible for that to happen? And yet it did? Does that defy the laws of physics? No. Is it a pattern in Apple land? No.
But this whole idea of seeing patterns where there aren't any, that's just creepy. They will release new products when they have something to release. They will try to cluster product updates when they can, but it's not a hard rule. There are just super obvious marketing reasons for that, I hope this is clear to anyone above the age of 5. And... guess what... it also strongly depends on their suppliers, like Intel and AMD currently, when they have new updates ready. Or other things, like keyboard class action lawsuits maybe. There can be all kinds of reasons for why Apple may not be able to perfectly control release schedules according to patterns invented in forum posts. Not saying they are defensible or honorable reasons, but I'm pretty sure that there are rational reasons.
And guess what.... Apple could end up making a surprise refresh in August even though it has never happened before. Not saying it's likely or something they would prefer, but it's certainly possible.
All of this makes it a completely futile exercise to try to guess when a particular update will happen based on past refresh timings. It made a lot of sense to expect an update at the WWDC. It makes a lot of sense to expect an update in October. But there have also been many Octobers when Apple haven't refreshed any MBP's. It's just silly to mislead people to think that there is another pattern when there so clearly isn't.
Now as a bonus quiz, try to figure out whether June and October are just chosen at random or whether there is some marketing reason for that.
