I think player agency is the whole point, but in order for the players to really have agency they need information. I don't even bother to obscure it anymore. I don't care if they decide to swallow the True Names hook in this example, but for me there is no reason not to tell them clearly that's what they are. "See, it's a big tasty worm!"yeah It means over the last 5years (not counting the 2 book adventures 1 ongoing) I have thrown away dozens if not 100 plots because I leave a clue and the PCs walk past it. Sometimes it's an NPC, sometimes it's a tree with demon names and sometimes it's the book of secret arts sitting in the bards backpack unread for 7 levels...
sometimes though they circle back. Myabe in 4 levels they will be around here and pay more attention then, or maybe this is just a foot note.