If 4 cars per update on average, then this means at least 10 more updates... So at least through2025.
Of course if there new cars .... Sprinkled over several updates, this will push the GT7 play time through 2026....
With MS no longer in the console war, there is no longer the rush and the drive to release the next console PS6, therefore I suspect Sony might continue to rely on the PS5 and PS5 Pro for the next 5 years, to avoid having to lose development cost of the PS6 ...
PS6 could be released no earlier than 2030
Which means either GT8 won't come out at least until 2030 or later...
OR
GT8 could be still playable on PS5 and PS5 Pro...
Which is my preferred option, so that I don't have to upgrade and still give a lot of you to catch-up and get the PS5 and peripherals....
The push for PS6 I suspect would require too much financial burden on all parties....