I'm from Serbia, I'm very much pro EU.
I'm thinking even if Vučić falls, and the pro EU government comes in power, we don't know how long that will last. Milošević fell in 2000, only for almost the exact same people came back to power 12 years later.
I think it would be great for Serbia to join EU sort of like Norway (I know Norway is not a member of EU, but is part of a single market, and free movement of people, goods etc…
This way the EU would have leverage over Serbia potential nationalism, but still if they came to power they couldn't veto important EU decisions.