Well its hard to say. Hino gives us NO clarification for ANYTHING in the final chapter so everything is basically up for interpretation.
Like i said before, Yori has a fiance, shes had one since the beginning of the series. So its really hard to tell if she went against her parents wishes and just went off with Kaito. It IS a possibility, and Hino has given us no definitive answer, so i guess you can basically take what you want from the scene with those two together.
Im just not so much for it since I kinda sorta ship them, though Kaize (Kaito X Zero) has kinda become my OTP since Kaito is the only person i think is deserving of Zero ~
Thanks for the question ~