Okay. for that to be a reasonable take: curing deafness must then destroy culture.

would that ACTUALLY happen, though? I challenge that assumption.

Take this hypothetical scenario: magic... magically all deafness is gone, suddenly and instantly. Would this destroy friendships? Would this erode personal relationships? Would this destroy (the very useful invention of) sign language? Would this destroy books or media? Would this devastate financially members of this community? would this kill anyone?

Well, besides the secondary effects of suddenly hearing, potentially leading to accidents. Do you actually think any of the above would happen?

I don't actually see anything like that happening. This is conservatism dressed up wearing a minority's hat. This is staunch resistance to change because of fear of lacking the familiar experience using a gross comparison to prevent reasonable analysis.

But I also believe in personal choice. Mandating conversion is not a power I want to give the government in any capacity. I just do not see the 'genocide' argument.

This is an example (like Christianity) about how horrible ideas attach themselves to identity to prevent their excision from their host. If you don't think Christianity is a good idea: suddenly it's a personal affront to them. If you don't think being deaf is an advantage or neutral: suddenly it's a personal affront to them. Be wary of anything attaching itself like this to your identity: you usually get infected when you are too young to have defenses.