Well, if Neal or MRJ was to return not as a vision but for real, that would trend, even if as a neal twin, lol, bc in this show anything can happen, ouat fandom would be shocked and would make that trend, I mean they trended Neal/MRJ stuff in the past, with hope for Neal? Or when 315 aired Neal and Bae tags trended worldwide. Ask MRJ used to trended when MRJ did those, didnt trend in 312, bc everyone already kne whe would be on it, heck they even had somehow the scene in advance bc someone posted online. Also, this is tv line, with example of 312 blind item, when they called Neal fan favorite? many said could not be Neal bc he was not a fan favorite, so these blind items are written to generate readings so they have to exagerate onwhat they write to get people to read it.
Although, wonder if in the case if this was ouat whivh i dont believe, and the scene was filmed in August only, if was related to do with the fact that they reshoot scenes in all the other epis and somehow appears they filmed them, while filming 605 and 606.
I would thought CW shows with Shatner( in supernatural or flash), but they only start in October ,I think, the item said the scene was filmed in August, for a September premiere, may be Sandra oh return to greys , there are rumours she is to make one appearance, i think was not confirmed yet, bc if they still didn’t confirmed may be her, Cristina yang is a beloved character that would trend for sure.