Had Emma not saved Marian….everybody, by Core Cast means, would be happy! There would be no worries!
Except that Robin would be ignorantly engaging in a relationship with the person who killed his wife, and that’s definitely not “no worries” IMO. If they want me to be OK with OQ, Robin and Marian need to have an amicable split, and she needs to live, and Regina has to regret what she did in the original timeline and realise that she can’t just demand a work around or do even more nefarious stuff in order to get her what she wants, (like trying to rewrite the book to fix her life). Even then it’ll still feel wrong to me because Regina did originally kill Robin’s wife and the mother of his child, so I can’t see how he could be with her, but if they’re gonna insist on having pixie dust predictions being infallible, at least circumstances are such now that the full truth of the past can be known and dealt with, instead of Robin being blinded to the past actions of the woman he’s gonna be with.