TwoSix
Everyone's literal second-favorite poster
It really doesn't. Players don't have expectations of certain items being in the game, so the loss of the potential to gain an item later doesn't carry a lot of weight.This twist creates capability of drama and invention. There will be frequent flashbacks to the first 10 minutes of the campaign where the players held their magic items, stressing their loss and irreversible absence. It also may be a clue in of itself—say the PCs meet a roguish man who says “there are more amulets of the planes out there”—they’ll be able to deduce he’s a shifty character just saying what they want to hear (the truth being there was only one and now it’s gone and can’t be recreated)
And honestly, knowing that the DM has already pre-scripted 6 plot twists would be enough to make me walk away from a game. I have HBO Max and Netflix for pre-scripted dramas, I prefer my RPG experiences to be collaborative and improv-style.