Correct, but this requires miner collusion. If just one miner says no (or isn't contactable by the colluding party) then the transaction can make it into a bloc

Correct, but this requires miner collusion. If just one miner says no (or isn't contactable by the colluding party) then the transaction can make it into a block. If this ever became a practical issue, which I doubt, then censored people would only need to switch to any coin that supports stealth addresses. Edit: I also suppose, the colluding miners could also try to mine a competing fork to censor a block. This would be rightfully called out as a 51% attack attempt, though.