Interesting; the assumption of Maya entering the picture much earlier than anticipated indeed can be used to explain Niki vaguely recognizing Maya and the mysterious playdate girl without pink hair simultaneously. While Niki technically could have just unintentionally met Maya at any other time point, I highly doubt Niki would have enough mental capacity to give two shit about it. So if the source of Niki vaguely recognizing Maya indeed comes from briefly meeting her before, some time before the accident seems to be the most possible.
What gives me much to think about in fact is that this idea also opens window on the timeline to let Sekai have a chance to meet Maya. The pair meeting each other may not bear any significance, but I always wonder why Sekai in different happy events exhibits such high toxicity toward Maya if they never met before Sekai died, and this idea enables just that. Of course the possibility of a ghost Sekai always lurking around Akira, watching him fucking Maya, and accumulating distaste remains tall (as well as the possibility of interpreting these happy events on an overly facial level), but now there could be an alternative that doesn't immediately resort to the supernatural or the metaphorical.
The weird thing is that her toxicity and hate is only shown towards Maya. When it comes to Niki & Sensei relationship in Happy Scene "Good Boy" or Niki's "Glasswalker" & "How to Make Love Stay", it is more like she is playfully taunting them
In their recent conversation at the infirmary (Chapter 3 "Girls Just Want to Have Fun") she doesn't seem to care that he is fucking and making his own harem, in fact she encourages it. Yet for some reason she hates Maya specifically.
It's not entirely confirmed, but it seems likely that Sekai hates Maya for one major reason:
- Maya broke Sensei beyond repair, after the Accident.
Noriko reveals a lot about Maya, but one of the major things is how she believes Maya fucked Sensei up for good:
As far as has been revealed, Maya was the one who pursued the relationship with Sensei:
We also had Pareidolia seemingly disliking Maya for how she groomed Sensei:
And we know that Maya tried to keep those that loved Sensei away from him, apparently convincing him he was all alone:
We also had Sensei mentioning he was willing to be Maya's toy last update:
And, Ami has brought up that she suspects something must have hurt Sensei to cause him to stop tutoring:
It seems like the only thing that could have hurt him, and the main thing that sends his body into shock, is him remembering his relationship with Maya.
As fucked up as it sounds, it seems like a Wizard took advantage of a mentally ill man in his 20s, and broke him into his modern self in his early 30s.
Overall: Sekai probably dislikes Maya for what Maya did to Sensei mentally.
Not to mention, if Sekai is just some kind of hallucination from Sensei's mind, it might be the part of Sensei that regrets and dislikes what he did with Maya, personified. Just, you know, blaming the Wizard.