Even Damon doesn't really tell the MC everything.
Damon doesn't tell the MC
anything.
There's a pattern in this type of stories, and it's usually to put these close but shady characters under a really guilty shadow over a certain event (in this case, leaving without a word), so that the audience/players blame the hell out of them, only to find out later on that everything was done for MC's sake, with a very convoluted way to explain why the MC was completely left in the dark.
The problem there is that you then have to come up with an explanation that 100% justifies both the abandonment, the total lack of explanation, and a willingness to speak to other tangentially related people but
none of those people being willing to explain either.
If you can't pull that off (and honestly, I'd argue that it's nearly impossible to do well in any setting that doesn't involve magic, where you can justify omniscience on the part of an antagonist and threats to kill your loved one if you even attempt to explain), it kind of makes the entire thing feel like shit writing. And doesn't really do much to negate the anger and sense of betrayal the MC should be feeling over the whole mess.
Unless we get an explanation like mom left a note saying why she left but dad intercepted it or something (and even then, I'm still kind of calling bullshit), I can't imagine a scenario where she would both have to leave without warning
and was completely unable to explain why. Not even something contrived like "I was caring for a patient who was in the Mafia, and they told me I had to go treat him in hiding and couldn't tell anyone why I was leaving or they'd kill them!", because Mafiosos aren't psychic or omniscient. There
would have been ways to at least semi-explain without getting caught, and without causing an emotional meltdown.
If anything, "I did it to help you/protect you" is going to feel like Damon's "I need to fix things" excuse. When everything you're doing makes things drastically worse, your good intentions kind of stop mattering compared to the actual consequences.
And if something like that happens and the MC immediately forgives her (and probably blames himself for everything) without giving the player the option to call her out or reject her, the ensuing rage-storm will be legendary.
Thing is, she knows more about the MC than even the MC knows about himself. Why? Because Damon can't keep his big trap shut.
Does that even really matter, though? We've been explicitly told that Damon and the MC never really talk about personal stuff. Damon's not really going to have any deep or meaningful things to tell Mira about. Most of his stories are probably going to be along the lines of "We got drunk and did a funny/stupid thing!" or "We hung out and cool thing happened!". That combined with the fact that Damon was almost certainly talking the MC up a bit implies that anything Mira learned about him outside of direct interaction is shallow at best, and at worst is outright wrong.
Again, she loves her own
perception of who MC is, not the actual person. And that perception may be at odds with who the MC actually
is. Worse, her perception is likely going to be at least a bit self-serving (an idealized version of someone is the perfect person to project your own rescue fantasies onto - he's the white knight who's going to save her from her tower so they can live happily ever after).
That's not really a recipe for long-term happiness and relationship success. That's a recipe for disillusionment.
And it's more or less a direct repeat of the relationship with Naomi. In both cases, the girls are more in love with the idea of what you represent to them than they are with you as an actual person. Assuming they even really know or care who you are as a person at all. And at risk of completely falling apart the moment that reality conflicts with the fantasy.
In her own way, Mira may be using you just as much as Danielle or Ada are, even if she's not conscious of it.