Unless we're getting another mainline game coming out in the Holiday season I'm not expecting a summer release for Legends ZA. I can't see them skipping the Holiday season three years in a row.
Thing is, PLA released January the same year SV released in November.
Even though it had most of the year to itself, it still had a pretty short support life especially by the time of marketing for SV.
I do not see, at least in terms of gen 10, another game being marketed for release the same year they'll be marketing PLZA. Because GF would not be going back and forth going "New Pokemon/Forms for PLZA" and then "New Pokemon/Forms" gen 10.
So if there is another game, it'd most likely be a remake/port of a spinoff.
PLZA is going to be marketed this year and August could be a possibility for the sake of no winter release for 2024, a not so very half way marker for releasing a game. To add as well, to release a game a couple months after PLZA would kill sales.
However we'll have to see.