Just to throw this out there, there's something I don't think has been talked about when it comes to Io's recent events.
It wasn't necessarily about
her. By that, I mean it was about
Uta:
Io looks up to Uta, and believes she would actually be dead if she never met her:
So, it seems like Io was trying to protect Uta from Sensei, by becoming Sensei's tool, after finding out that he's holding on to a wizard pic of Uta.
In other words: Io was trying to keep him from fucking up Uta, by offering herself.
It's all she had to offer:
The "parenting" stuff just forced her to stop being in denial about him. He reminded her of her mother. Then
he could even use the same words
she did:
In another timeline, this may have ended on a happy note:
But, even leaving may lead to problems. Albeit, I suppose we'll see.
I have not said that, but everything I said about it fits very well with this. By that I mean that Io spearheaded the whole conversation, shot down every Akira attempt to disengage, and was overall dead-set on it happening. Also that she was out of her mind the whole time since the moment Akira tried to justify Ami being important to him by using a comparison. All of those fit with her being on a mission.
I don't think Uta was the sole reason, since if it was, Io would be incredibly misguided (if not stupid). Uta never needed this help, since Akira being the way he is is ultimately good for her. Uta herself says that, in prior conversations with Io, it was Io that seemed intent on Uta dealing with this news in a manner that was very different from what she seemed to take from it. But I think we can all agree that Io wasn't thinking straight, and that in that sense protecting Uta was certainly part of it, since she said it herself (it just doesn't doesn't match with reality, but then again, barely anything about the stomachace conversation matches with reality because Io hardly listens to Akira).
I think there's a chance Io won't be ruined from this, but I think it would be interesting/ironic/tragic for her to be ruined form realising that her efforts were absolutely misguided. Uta never needed her "protection", and Akira, having been molested as well, would never have left her because of that. In that case, either she went through with it for no reason, or she "tarnished" herself by vomiting her entire backstory on him, pressuring him to have sex (which he refuses), and ultimately she would also have put herself in that position for no reason. Selebus might choose that route to link both options.
Unintended though they may have been however, Io's events had one important repercussion, which was the way Akira handled Uta's conversation. Uta already didn't have much of a problem with it, and was really just confirming. But the fact that Akira breaks down in front of her definitely makes Uta's decision easier, as she can relate better to someone that displays being actively broken about these issues than if Akira had been more composed (like it was not a problem for him).
If the timeline was also reversed, I think it lends credence to your take, because if during the conversation Akira had been "Io, Uta's fine with it, we already talked" - Io would be hard-pressed not to slow down. I don't know that she'd give up, but it would definitely change things (just as Akira's Sekai's reveal forces her to slow down as well). In that same token, if Akira had actively broken down in front of her, that would probably have also changed things.
As it is, Io was dealt a bad hand and made sure to make the worst of it. And in doing so, she ended up providing Uta and whoever came later with a better hand by default.
On a final note, a wonder to which extent the world itself/whoever speaks to Nodoka foresaw/intended for this event so that Akira could reveal Sekai to someone for the first time:
The event is called "trauma bond", Akira is the only one that would have the same trauma as Io, and what Nodoka says can be completed as "spilling traumautic events from a character's past would serve no purpose other than to
serve as trigger to have the protagonist talk to them about it in a one-on-one conversation later". Which is what she tried to do, but was rejected, and that served as a trigger for Akira to have the conversation she wanted to have. If not for Nodoka, even with Uta's picture, Io's events would never have happened. Was that happenstance however? Or was it by design?
