Now on the topic of who may fight who in the league, i would say that neither Trip nor Stephan would fight Bianca as she had fought them once before already. So my guess is that Bianca would either fight Kotetsu or Virgil. It is also possible that she could fight those 2 and defeat any one of them during the league.
Trip may most likely face Stephan or Virgil. For some reason i don't think he would be put against Kotetsu.
On another note, i wish that the Unova League has a group round similar to the one we had in Johto League, which would allow the top 2 (if its a group of 4) or top 3 (if its a group of 5) to move on to the next round.
This would allow us to have multiple rival battles during the league without anyone getting KO'ed early on.
Like for example, in a group of 4, they put Bianca, Kotetsu and 2 random trainer in one group. Both Bianca and Kotetsu would win against the random trainers, and then Bianca would defeat Kotetsu. But both Bianca and Kotetsu gets selected for the next round as Bianca would have 3 wins and Kotetsu 2 wins. Then in the next round Bianca may face Virgil while Kotetsu may face Stephan.
This way we would have a lot of rival battles. The reason i want this is because i was sad that Barry got knocked out early because of his one loss against Paul in the first round, and after that didn't get to do anything.
But unlike the Sinnoh league were there was only 2 main rivals (Nando and Conway can't be counted as main rivals though), there are about 5 main rivals this time (wonder why Burgundy isn't taking part in the league, she did start out as a trainer to take part in the league and also had won a badge), so it would be bad if some of them just get knocked out early because of just one loss in the first round.