Silent Hill is, in a way, a "semi-Isekai" game. I mean, I guess Silent Hill is located somewhere in America but when that siren blares you're sent to a decayed reflection of that town which may as well be in another world.
So Pyramid Head, who himself was a manifestation of James Sunderland's psyke, is probably double-Isekai'd to the world of 404 RE:SET and is now some confused somebody who has to lead a revolution with a bunch of game franchises that have nothing to do with Konami.
404 Game Re:Set has collaboration with Bandai Namco, Capcom, and Taito so I think Konami still could make it too.
But Konami's representations are probably Twin Bee, Bomberman, Parodius, Frogger, and Gradius, not Silent Hill since Silent Hill has no arcade games.
That's too bad, since I think it could be funny when MC met Pyramid Head.