Yeah, where the analogy with games like Fallout falters is that, in a collaborative RPG it isn't so much about moral choices as about moral debates. Because the player is not just choosing for themselves but for the entire party, and because they're not just making that choice in the privacy of their own heart and PC but doing it in front of others, the choice tends to lose the sense of immediacy and intimacy that it has within a single-player game - it goes from being a fundamental building-block of the type of character they're trying to play, to being merely one voice among several, trying to second-guess, rationalise and out-talk the others.Don't stint in the time you spend on this concept in Session 0.
Some players will take a plea over the radio as "this is the adventure the DM planned" and will automatically take it. You need to make them realize that they must be willing go to their own thing and go "off script" of what you are laying in front of them if their characters want something else.
Another thing is this can easily end up with sessions full of moral debating and a party that should split except that they are the PCs. Some inter-party drama is good as long as it doesn't lead to inter-player drama, but moral gridlock on a regular basis and characters who would leave (or shoot) each other if it wasn't that they were fellow PCs doesn't make the best game. This is hard, as even if the players are up for it upfront, it may and likely will wander during actual play.
It's never going to feel meaningful in quite the same way, and that eventual after-action report won't feel nearly as personal or character-defining.
I wouldn't say don't do it - I'd just say know what you're actually going to be achieving, and don't try to make it something it's not.