It's a cool idea, i imagine this as an automated check for all party members at the beginning of the fight and you can then examine if the game tells you you realised something interesting. it would even reduce the combat time if you realize the weakness early and action accordingly. dnd has a couple of monsters with high resistances and vulnerabilities, knowing about those can be a game changer at the first encounter with those creatures. also as you said this would encourage to have a diverse party as then all of your party members would be expert on different enemies
The game already has the examine interface implemented so it would be nice if somehow it would be layered how much info you can read from there. even books about creatures it could make more worth to read.
