The "real" Gabi path doesn't work on the path where you blackmail her.
The blackmail
means you banged her once, then use this info to get Layla approved in her class.
Gabi isn't very happy about that, the relationship ends and she resents the MC... i guess there's still reason to go after Erynn in the blackmail path once she figures out that there's something going on between her and the MC.
The "real" Gabi path, you have an ongoing sexual, sometimes romantic, relationship with Gabi...
She often takes notice(and has some jealous reactions) to how you behave with the girls in class, specially Layla.
Surely she'll take notice that the new teacher has the same favorite student she does
Of course there's the boring variation of no Gabi... she doesn't pay much attention to him, he gets good grades... no reason for her to interfere with anything.
I hope Erynn begins her internship soon, this coming week already, it has loads of potential for messy situations.