Couldn't have been anyone but Bianca. They need Rhea to go in there against a heel/heel-adjacent person who can take the loss, get physically outmatched in a way that would look impressive without looking obvious, and who isn't so beloved that they'd turn Rhea going against them. The Tegan/Dakota program pulls them both, and unless they wanted to hotshot Chelsea Green into that situation on some Lacey Evans shyt - which, thankfully this is NXT so they won't - there wasn't any other choice. Rhea goes in there against Io, she's going to get booed. Most the rest of the women are too small to give impressive title defenses against for her first one... had to be Bianca.
I was watching this waiting, because if Io won, then they were probably sending Rhea up rapido-like. Told me at least they are gonna give her time in NXT.
But man. Between Rhea, Dream, Tegan, Toni, MJF and a bunch of others, the under-30 range in wrestling right now is some shyt, ain't it?