Everyone on Smackdown needs to stay because they're finally doing a Smackdown PPV in Baltimore for the first time since the brand split, and I swear to god them nikkas better not move anyone I want to see to Raw after not sending them here for two fukking years.
Being more serious, I was just thinking today that I don't really see much need to do a huge shakeup like they did this year. Most people on the roster have settled into a nice spot and those that haven't (midcarders mostly) probably wouldn't get used much opposite show either.
But, if I absolutely had to do a shakeup...
To Raw:
Carmella
Natayla
Becky Lynch
Dolph Ziggler
Randy Orton (there's nothing for him to do on Smackdown anymore)
Breezango (provided the rumors of The Shield breaking up post-Mania are true; without them, there's a huge hole that opens for top face team)
AJ Styles (much as it pains me to admit it, he's probably done on SD after Mania)
Baron Corbin
To Smackdown:
Bayley
Alicia Fox
Sasha Banks
Elias
Samoa Joe
Finn Balor
The Miz w/ The Miztourage
The Club
Seth Rollins (probably wouldn't happen in a million years, but I think Seth would benefit from a new environment)