I thought about this too, but this Sensei DOESN'T REMEMBER THE PAST, so it still DOESN'T MAKE SENSE.
We never even got a moment that showed just how much he liked her if that was the case, he only told her that he loves her, but never, in any internal monologue or conversation, do you ever have the feeling that her dissappearing would do something like this.
Maybe we are being prepared for a big reveal, but this just stinks of bad writting right now, a case of tension without causation.
Well, Sensei did imply that Ami and Maya Prime were the two most important people in his life through Nao-Chan:
We also have him ditching Noriko for Maya at the beach, but later panicking then admitting he's scared of a future without Noriko:
Noriko still being someone surely below Ami and Maya in Sensei's eyes.
There's also how he almost broke down when Maya Prime nearly missed the 4th Reset, mentioned doing the resets with anyone other than Maya and Ayane would feel wrong, in the 5th Reset, and basically spent the time from Beachmas to Maya Prime's demise in the 6th Reset, risking his life by trying to get her to say she loved him, and give in to him.
Recently we also had it revealed that Maya's bday in Chapter 2 is where he had his happiest memory. (Basically since near the end of Chapter 2 to the end of Chapter 3, Sensei's love for Maya Prime was sprinkled throughout.)
I'm not entirely convinced that regaining his memories would actually increase his love for Maya, though. It's Maya memories (Post Tutoring) that seem to break him. Noriko and Ami have also seemed to hint at Maya doing something to hurt Sensei around the time he stopped tutoring:
What exactly happened and how New Maya is going to react when she finally realizes Sensei is "cheating" on her, are two things I'm looking forward to finding out.