I think I should have been more clear.
I agree with you, the whole point of inquiring about your ghost is to learn. I do however believe that it is important to know what you were ghosted for, i.e. not following a sequence, landing on the wrong runway, etc. etc. A simple check in the logbook should accomplish this and is why I emphasized it so much in the original post.
As for the part under ‘If all else fails’ what would you say about wording it as
While all controllers are expected to explain their reasoning for ghosting, not all controllers may be willing to reverse the ghost.