I do sometimes limit how much information can be relayed in combat - no 5 minute long discussions during your turn - and I may not do a complete info dump until after combat. For example seeing a grizzly bear I remembered the basics of talk calmly to make sure it doesn't get surprised, don't run, get pepper spray ready. Told the other people that if it does charge, just stand still (they frequently bluff charge).
But did I remember every detail about bears that I know? Probably not. Just the ones relevant to seeing one twenty yards away with no barrier between us and the bear.
So in D&D they may see a troll, know they have to use fire to stop it's regen. They may recall afterward that trolls in this region trolls are extremely rare and one hasn't been seen for decades. They may recognize the markings as being trolls from a region to the north or whatever other tidbits are useful for the story.