I wonder if the Platinum Trophy will be separate between Shenmue 1 and 2 on PS4 or whatever it's called on Xbox.
Found this picture online and it seems that for Xbox, the games will be separate applications.
https://pbs.twimg.com/media/DhKbS5cUcAEuNbW.jpg
I think you're right.
https://www.microsoft.com/en-us/p/shenmue/bz75xhfdz14q
https://www.microsoft.com/en-us/p/shenmue-ii/bp9lqqw7q0mz