Does anyone else want Zoey to come back and throw a wrench in things? She'll create a interesting conflict with MC given their history.
What would that be though? MC has said he never really thought of her as a girlfriend so that's off the table, she's been gone a year and last sent him a photo 6 months ago when she looked basically the same so she hasn't had his baby and he's never kept her a secret (although he's only gone into detail with Bella)
If anything, a reappearence might serve to make him realise that her feelings ran (past tense, she's over him now and very happy in her new relationship) deeper than his and be the catalyst that makes him commit to one of the LIs.