Among other things, the survey includes a question asking if cross-play would "make the PC version more interesting."
Monster Hunter Rise, like other games in the series, includes an entire set of hunts designed exclusively for multiplayer. Including cross-play makes it easier for people to find hunting partners and take on high-level quests.
While it might seem like a natural feature to add in the game, Monster Hunter World, Rise's predecessor, doesn't include crossplay despite being available on three separate platforms.
Capcom Releases Cross-Play Survey For Monster Hunter Rise
Though the survey alludes to some possible features that might be introduced in Monster Hunter Rise in the future, it's still just a survey. There's no confirmation of what Capcom has in store.
However, we do know one other, major feature headed to Monster Hunter Rise in 2022, and that's Sunbreak, the game's first paid DLC expansion. Sunbreak will release for the Switch and PC versions simultaneously and adds new monsters, quests, and more.