I’ve seen a prot paladin do this but they were definitely healing themselves and throwing out heals. I think it’s a bit different to say “no heals” then it is to say “no dedicated healer.” I would suspect those other keys have some dps/tank that is throwing out heals. Especially on a bursting week like this one.
If anything, this helps show the disparity between healing classes (those that can contribute to dps) and how important dps is for completing keys.
My humble thoughts. Highest key I’ve completed thus far is a 16, so, keep that in mind.