I'm as close to certain as I can bee that this is impossible. It would be a safe road to bankruptcy for any insurance company to offer anyone to get an insurance and then directly sign up for a surgery, US citizen or not. It's not an insurance if you sign up for it and already know what you're gonna claim. Then it's more like a rebate system, which I'm sure they're not in for.
How could they stop you? If they do an evaluation for pre-existing conditions, you would declare you have a crossbite/openbite/malocclusion on the list.
If they approve you then they become liable for any surgeries you get thereafter. No?
I guess the problem would be even if you got insurance they will try to tell you to go to jaw surgeon X at hospital Y for a budget job and then you're no farther ahead.
So yeah, probably impossible. Okay.