Imagine Lucy leaving Hank behind but when it's revealed he bombed Shady Sands and that she's his daughter the NCR kinda distrust her because she let him go (maybe even cooperating with him). Sure she can tell them about the mindwipe but they can also not believe her
As far as we know, the only people who know he was the one who did it are Lucy, Max, and Cooper. Cooper has exited stage right for the time being, so that leaves Lucy and Max, and I don't see Max revealing that information without Lucy's permission.
Lucy, with her need to be honest, might spill the beans herself, maybe to Captain Rodriguez. I could see her confiding in the captain in the hopes of keeping Hank safe, maybe? Or maybe Lucy would use him as an example of what the chips can do, so she can warn Rodriguez about what he'd set in motion.
If the truth does come out, I think it'll be by accident, or maybe during an emotionally charged moment. Maybe during a disagreement between Lucy and Max about what ought to be done with Hank, or somehow Thad finds out and he brings it up at an inopportune moment or as a kind of 'gotcha' where he's trying to prove Lucy isn't as good a person as Max thinks.
Whatever happens, I think Lucy is going to have to accept that her father's fate may not be up to her alone.