I think Gwen more firmly placed in 616 would definitely be a hard sell, because I think the Earth-65 feel and the versions of 616 characters in that universe was a big part of her appeal, and I'm not sure if they'd be able to capture that again if she moved universes.
It's not even like with Miles where he at least had a few unique supporting characters to his name before the jump happened.
But, that being said, I think it would be interesting to see other people from 616 who knew Gwen would react to Earth-65 Gwen. Like Mary Jane.