Anyone who has owned a Classic Model S (pre-AP) certainly knows what happens to upgrades, they will be less and limited mostly to whatever system is the same in old cars as in the current cars. So when the current CID is retired (possibly soon), it seems possible even less upgrades come to these old cars. It makes less sense for Tesla to upgrade something that is no longer selling new cars and there is history that they do let this affect their upgrade plans. (The CID is just an example of software update history, not related to AP of course.)
So yes, there definitely is a concern what happens to AP1 and AP2 ugprades now that AP2.5 is out. AP2 should be safe on some level as a subset of AP 2.5 due to the promises Tesla has made, but who knows... Tesla does have a history of missing promises on older hardware and using newer hardware to fulfill those promises, leaving older owners in the cold (P85D/P90DL Vx performance is one example, missing promised features in AP1 another etc.).
I think Tesla is walking the tightrope of saying just enough to the public to keep the sales going and limit liability and risk of osborning products by not saying too much or being too exact. Talking to Electrek just enough to keep the most knowledgeable new buyers and enthusiasts buying their cars, but not say or announce too much to the wider world, would fit that... It is IMO all about keeping those quarterly sales moving and staying vague enough on stuff so that they can change things whenever they want...
There are tons of cars e.g. in the international pipeline with older AP hardware and any other "missing" things the Model 3 changes have caused them to miss that Tesla wants to deliver. Too much publicity could harm that...
Just speculation, of course.