I believe Bayley will beat Carmela but she will put on a great showing and move up to the main roster with Cassidy and Enzo who at this point are established characters good enough for the main roster.
I believe Eva Marie will be back up to the Main Roster after the Royal Rumble. She honestly can bring Nia Jax up with her because Nia and Eva are pretty much a solid duo that will push Eva as divas champ rather people want it or not lol she is this generations Sable.
Uhmmm... Cameron is in an iffy spot because she's apart of a generation of divas that honestly should be existing soon. I think she is good for NXT because she is a solid performer but she's in the same boat as Emma. I'm not sure if Emma will ever return to the main roster.
I personally don't think Carmela is ready for the main roster as a wrestler but she's fine in terms of her promo abilities. Maybe she'll surprise me against Bayley.
Eva definitely isn't ready for the main roster and I think Nia needs more time as well. I don't even think Nia has even had 10 matches.
Cameron still wrestles as if she's afraid to mess up her hair which in turn affects the quality of matches she's able to have. Emma's problem when she was on the main roster had less to do with her and more to do with creative.