The update just established the only people who may know how to do so are the Psions.
You are noticing the red herring and not the implications. What you should be taking from this update is:
1: This is the version of Blackstar that cannot fly because of a disease, and not something genetic.
2: The effects of the disease can be reversed.
3: The people on the planet where OL currently is used to be able to do this.
Not stated in this update but in previous ones.
4: The planet had had its internet and mass transit systems destroyed, cutting off communication.
5: The planet has had its industrial infrastructure gutted.
6: These factors make her statement that now only the Psilons have the knowledge to fix her suspect and unreliable.
7: Vega does not have anti-lantern scanning defenses slapped everywhere willy-nilly.
8: Power Rings can scan an entire planet for information, like books buried in rubble, and inert or isolated computer drives
9: It is vanishingly unlikely that any and all trace of the details of this medical procedure were eradicated planet wide.
and isn't sure that healing her would actually help the situation.
He be giving her flight literally every other person on the planet has. It not like healing her injury will lead to her conquering the planet with her awesome power of
not being a cripple! But it could help her overcome some of the issues that lead to her becoming a supervillian in the first place. What are the words that just freaking came out of his mouth?
"When I do something, I stick with it until it is done. My aim was to help you. If there is more that you require in order to-."
This is something that is bothering her, which he knows from her flash of red when he mentioned Kon being Solar Powered. This is something he can do, that her people currently can't, won't appreciably make a difference if she does turn supervillain, and could very well be the difference from canon that keeps her from going over. Why are we even having this conversation? This is a no-brainer if OL is in any way sincere about the words that are coming out of his mouth.