Io has implied that even if she's trauma less, things still wouldn't work out between her and Sensei:
It could just be her self deprecating, but I dont recall her mentioning that her trauma made her ace. It may have just enforced her sexuality.
Honestly, you can probably kiss Sensei's harem goodbye if Ayane is actually in control. She's straight and monoamorous. I wouldn't even be that surprised if Sensei only wanted her, now.
Not to mention, "Healthy" girls aren't easy prey for a predator, anyway. The only girl that might still be effed up enough to want Sensei, is probably Ayane.