Luna was intended to be a small sequence, with the collar having a potential use later in the story. There may be endings resulting from others putting the collar on you again, but there is no plan for a full third route.
I can dream!
I was a bit sad in the ending when its mentioned Luna has kids(sorry if this is a spoiler mention) that they were strictly human, was imagining that since MC-kun is special somehow since hes the only one that has turned back from wolf form(as mentioned by others), Luna's kids might have been like a perfect fusion by being able to either transform into either form, and not be turbo sluts and be normal, so its not a complete bad end for either side of the player and human/wolf conflict.
It's less to do with the MC being special, and moreso the nature of the collar. Any other wolf made with the collar would have the same occur to them, as it prioritizes the human essence used to conceive. There might be some wolf traits that pass on, but they'd be so imperceptible they might as well be pure-bred human.