Question: Does Monster Hunter Rise for the Nintendo Switch and Microsoft Windows PC feature cross-saves and/or cross-play between the two platforms?
Answer: No. Considering the Microsoft Windows PC version was released on January 12, 2022 (nearly six months ago which is enough time to fine tune this feature), it's not looking like Capcom will ever offer cross-saves and/or cross-play between these two platforms
If they wanted to add these features to the game they would have most likely done so before they released their Sunbreak DLC, which was released on Jun 29, 2022.
This is discouraging for Nintendo Switch owners who logged hundredths of hours into this game and would like to upgrade to the Windows version with a smoother framerate and better looking graphics.
By the way, cross-platform features is available for may Windows and Switch titles including Among Us, Dead By Daylight, Fortnite, Minecraft, Need for Speed: Hot Pursuit - Remastered and Quake.