Just because a company has a financial interest in learning a piece of information doesn't make it legal to acquire that information in any possible way. Pasting a signature onto a different document sounds like a clear cut case of fraud.
I'm saying if I'm the insurance company, why would I offer disability insurance if I can't verify the existence or absence of a preexisting? condition
Furthermore, the insurance the person is asking for is disability insurance. Common sense dictates that they will ask for medical records, and therefore need a HIPAA disclosure document.
If what the poster alleges it true, I agree wholeheartly that it should have been more clear in signing up for it, but it seems odd that the poster didn't think that state farm would ask for medical release forms for disability insurance.
TL;DR, I think there's more to the story than what is alleged here.
Honestly, though, so many ads for insurance say you don't need a doctor visit, or health checkup, or whatever. I could easily see customers getting confused thinking they wouldn't need to give over health documents because the ads are deliberately misleading.
Just because a business's practice is obvious to itself and those in the know, doesn't mean customers can get fleeced because "they should have known better". Caveat Emptor is kind of bullshit with such high information asymmetry.
Being blunt, I think the poster has no idea how insurance works, and didn't bother to read anything while signing up. Now they are upset because they actually read it.
Or being less charitable, they did understand the process, and wanted to create fake outrage about it. You don't have to "be in the know" to get how insurance works. Nor to understand that an insurance company will want to do it's fact checking on someone as a condition to insure them.