From what I read, not all doctors perform band-to-sleeve surgery, and those who do don't remove the lap band. They leave it there and drain all the fluids from it, to make it inactive, and perform the sleeve.
I'm glad I don't live in The States, we have universal health care (Israel). Problem is my country really tries to be American and our governments have been draining the budgets from the national health plans. A lot of people who choose to go through bariatric surgeries pay for them with private health insurance. I have to wait in long wait lists because all the privately-insured people are using the same surgeons as everyone and pay extra for faster queues.