Sure, possible to an extent. Though, as far as I've followed production cadences of various planes around the world, it's quite rare for a model to be more or less stop production, until a different variant is ready to be mass produced. much more often the switch is done in parallel, gradually.
But I guess it's also likely that not one single reason is the right explanation but a combination of all the reasons listed. Sure, some of the drop in reported numbers of newly established units may be there due to a gradual switch to a new model. Another part may be due to out of date info and simply hidden info. And perhaps even another small part may be due to many units being established over the 2022/2023 period. we're talking 6 brigades for sure with two more rumored. And we're often seeing as many as 36 shelters at those new J-20 bases. That's possibly as many as 250 planes per 7 brigades, for example. It could be that it simply takes some extra time to fill all those units up with planes. Maybe the leadership decided that instead of starting the switch process to a new type, per brigade, they are now at a point where finishing up the switch per brigade is more prudent. TLDR, there may simple be a big backlog of spots to fill in, before additional units are set up for conversion.
