Panajev2001a
GAF's Pleasant Genius
It makes NO sense for any company to single out their previous install base in the first yr or so. Every generation the first round of platform exclusive games are on the new and old gen machine. You can't expect to release a multimillion dollar game just to have it on a new ps5 or xbx with no install base.
Not from the first parties. Some of the studios can support the tail end of the generation, like Sony has always done, and the rest can give great reasons why giving them £399 or so for their new console was a good idea. This also paved the way for third parties to start moving software over as people migrate to the new console... which you do want: the more HW:OS combinations you support the more it costs and limits you or some your customers are getting shortchanged.