Kicking off last night's Nintendo Direct was the announcement that Monster Hunter Rise will be receiving its first paid DLC next summer. Sunbreak has been described as a "massive expansion" and it's planned to include new monsters, stories, and locales. The showcase's host Yoshiaki Koizumi also teased that it will contain new hunting actions and quest ranks.
Besides a short teaser trailer, which you can watch above, not too many details were revealed on Sunbreak, but we have an inkling that it might function as post-game content like Monster Hunter: World: Iceborne given the imposing creature shown. Regardless of how it functions, you will still need a copy of the base game, as it's not standalone.