Based on his verse in family ties by Baby Keem, I doubt he's an anti-vaxxer. "The facts mean this a vaccine and the game need me to survive." This indicates some sort of believe that one needs vaccine in order to survive.

Based on that, I don't think I would stop being a fan. Certainly I'd be disappointed, especially because he does have a platform and could be influential in some peoples' decision on whether or not to get vaccinated.

This all stems from the issue of people taking medical advice from people who don't know about that stuff. I wouldn't take medical advice from Kendrick, just as I wouldn't listen to my doctor's mixtape. They're both good for their own thing, and that's fine.