I wouldn't mind an apology from Yash but I don't think it is necessary and I don't really feel the lack from the post-Mumbai phase either. They understood each other, where the other was coming from, and they moved on and made a better future together that would erase the pain of the past. If at all there must be a verbal apology, it should be a mutual one.
Don't even get me started on why the apology should have been mutual post-Mumbai too! π