Tbf, the Paper Mario return to form could simply just be some superficial attempt like not making all NPCs Toads, or just adding the Stage Plays and Badges back with absolutely nothing else done.
And with such high expectations I sincerely doubt any PM they produce is gonna live up to the other games in the series simply because people consider TTYD the magnum opus and there will always be tiny flaws people will find with a game. But I still do hope everyone is at least satisfied with the result if/when the PM comes out.
I do think a return to form is possible. Super Mario Party, BotW technically, Odyssey, and even the improvements from Sticker Star to Color Splash seem to paint a good picture for the Paper Mario series moving forward, and I'm glad Nintendo didn't just say, "Oh, it didn't sell well? Cancel the whole franchise"