This is of course speculation, because noone outside knows how moderation works, and noone inside is talking.
But we can be reasonably confident that not all moderation is undertaken by humans, and that not all human moderation is undertaken by highly paid staff of Quora: not a little work must be outsourced.
So it is possible that, in the workflows around answers, moderation got its wires crossed, with two separate people (or one person and a robot) both collapsing your answer. They may have done it for different reasons, or for the same reason. One may have left out the appeal link intentionally because of the heinousness of your offence, or they may have somehow left it out accidentally. (Though bad workflow engineering if they did!)
I don’t know about whether some answer collapses are appealable and others are not, I’m afraid; Quora appears to have changed its mind over the years: Why can’t we upvote or appeal collapsed answers now in Quora? Why are downvoted answers treated similarly to answers that violated Quora policy?