I'm expecting that they WILL NOT revamp the reaction system for the Bard class. Instead, I'm expecting that they will homebrew the Bard class so that it has features that are simpatico with the combat system as it exists in BG3. This tends to follow how they have treated previously revealed classes.

I'm sure that they will also add some magic instruments and Bard-flavored gear drops. It would be nice if they fleshed out the crafting system and perhaps added a new sub region to explore.