You can currently re-do N/H raid if you’re loot locked, I’d imagine the same thing would be implemented if this were added to M+. I definitely don’t think it should affect your ability to physically re-do the keys, otherwise score pushing would be pretty much dead in the water.
To be clear I’m arguing for this from a raider fairness perspective, you currently can’t choose to re-do bosses in raid for their loot at the cost of taking away one of your rolls later on. Maybe you should, maybe you shouldn’t, but I highly highly doubt that’s a bridge Blizzard would be willing to cross.
I think with the way raid loot currently is (even with the other restrictions you laid out) would tip the scales back too far toward M+ loot being too overpowered.
This is purely antagonistic and would almost certainly be bad for the pace of reward structuring but as an M+ devotee I also wouldn’t be mad if they just made raid loot (maybe just from N/H) infinitely farmable lol. It’d never happen, but I certainly wouldn’t complain if it did.