Bedrockgames
I post in the voice of Christopher Walken
But aren’t they? Don’t those methods undermine choice?
I don't think they undermine meaningful choice (at least not enforced alignment rules and the three clue: the players needing to figure out the GM's predetermine solution could well impact meaningful choice depending on what you mean exactly by that). With alignment the players are still free to make what moral choices they want in the world. Having rules governing alignment give some cosmic consequences to those choices (which I think can add more meaning to them). A classic example might be a player finding this character slowly gaining an evil alignment through his actions as he takes more and more selfish steps, sacrifices others to get ahead, etc. You are still free to make those choices. Another would be how a place like Ravenloft handled alignment where certain evil actions could attract the dark powers attention and result in players suffering supernatural transformation. My experience with Ravenloft is that added a lot in terms of meaningful choice (as well as characterization and development).