Yes. The save file is stored separately from the DLC. As long as you install the update, your High Rank gear will carry over to Master Rank.
In Kamura Village or Elgado Outpost, speak to the Palico mailman. Select "Add-on Content": Monster Hunter Rise Switch NSP UPDATE DLC
PC gamers also search for to play upscaled 4K/60FPS versions. Monster Hunter Rise Switch NSP UPDATE DLC
: Unlike previous titles, event quests in Rise are not time-limited; once downloaded, they are permanently available in your quest log. Cosmetic and Add-on DLC Monster Hunter Rise Switch NSP UPDATE DLC
As of mid-2023, the definitive update for the Switch version is v16.0.2 .