DQ12 could be PS5 exlcusive only if Sony moneyhats, which they could. They have an excellent relationship with SE.
If you really do think MHW has a shot at outselling rise in Japan then all you are doing is setting yourself up for a disappointment. You really think a title on a console with a miniscule userbase has a shot of outselling a similar entry on a userbase that is likely to be 3x the size?
Never said that. Furthermore, install base increases do not proportionally lead to increases in software sales.