Hope? It's Pareidolia that says he knows her by a different name when Akira says he's with Yumi outside the abyss (in the event "abyss").
I took it to possibly mean that Pareidolia was referring to the other person with Akira = Sekai. But yeah, if he was indeed referring to Yumi, then it's possible she's occupied Maya's place in previous cycles at the very least. There seems to be evidence from that following the last update, from the choice of song and angle being very close to "I'll deliver you to the fireflies", to the overall implication of them being a thing in previous cycles.
Ok yeah. It's probably Pareidolia disguising as or trying to, Wires.
But that idea of mine, that it's Hope, is so old, back then we mainly only had Hope and "maybe" Wires.
The thing with Yumi and Maya maybe being the same person somehow, is also because they are alike in some fields, their character. Also the family situation, or how they had to learn to provide for themselfes from an early age.
And since it was mainly you that came up with the slipping thing, which is funny because atm i'm watching the "new" Quantum Leap, maybe in some time before the game (a period between older cycles and now) Maya slipped into a diffrent version of her, which is Yumi.
But as is said all this belong to some theories i have and they are not short.
One of the only things i think that might be true for all theories i have, is that we might be dealing with just a handful of real entities and the rest just being different version or shards of those.