Yes. Absolutely, they should provide checks to determine if your character recognizes certain things. With Astarion, an Arcana check to determine whether you recognize the telltale signs of vampirism. For Shadowheart, Religion to tell whether she's Sharran. When you see a symbol of Mystra, a Religion/Arcana check to determine that it is her symbol. For people who don't know the symbols or the lore, especially, this is vital.
I will tell you quite honestly that I didn't really know Mystra's symbol when I was playing this game. Yes. I am a fan of Forgotten Realms, but I never really paid much attention to symbols for deities previously. When playing through the entire Arcane Tower, I had no idea that it was Mystra's symbol all over the dang place. Later, when I realized it, I thought to myself, "Holy crap! That's a whole new level of the mystery of the tower that I never realized. If they had let me know via a check that it was Mystra's symbol, during ANY of my playthroughs, that would have made a huge difference in my experience."
So it makes sense if my character makes a check and fails and then later is totally surprised that Astarion is a vampire, or same with Shadowheart and her being a cleric of Shar. Even if I, the player, know these things, my character might or might not depending on the check. That's the whole point of the checks, and it's why you waste your skill choices on such skills. If you want to know lore, you pick Arcana and Religion as skills so that when you encounter things like Shadowheart and her telltale armor or Astarion and his telltale vampirism, you can spot it and recognize it for what it is.
How cool would it be, too, if you called Shadowheart on her armor, and she made up a story about how she got her armor - a lie to hide her Sharran roots? Or how cool would it be to have to make an insight roll to see if she's lying right then and there. You might not even call her on it, but at least your character would know and not later be totally caught off guard by it.
It just absolutely doesn't make sense that we ignore these things, like our characters are totally idiots who know nothing about the world they live in.
