Received a threatening email from a former doctor's office

Location: San Antonio, TX

Yesterday I got an email from a doctor's office I'd been to maybe two or three times in 2023. It contained a pdf attachment with their office and contact information and this text:

"Dear Patients, 

As you may have heard Medicare has approved another 2% cut in physician payment. This has been followed in suit by commercial insurance companies. As of now, our patient population owes us just over **$**36,000 in balances. It is a federal requirement that we, as a medical office charge you what is not covered as part of your plan and any balances you may owe. If we do not, not only are we in violation of our contract with insurance companies; but you are also in violation for non-payment. As it stands, we will be aggressively pursuing patient balance payments for the next 30 days. If you do not pay your bill, we will have to contact your insurance company and this could result in loss of coverage for you and/or dependents. We know things are difficult right now financially but we cannot continue to sustain the clinic without the necessary funds to pay staff. 

Please reach out to our staff as soon as possible to pay your balance and avoid being reported to your insurance 

company. 

Thank you. "

It's possible that I do owe them overdue co-pays though I can't say for sure because I haven't received any notices that I can recall, especially by email. I've searched my inbox. I'm not particularly worried about them contacting my plan because it's entirely different than what I had at the time. Really it just seems extremely shady and it pissed me off when I read it. This is pretty typical of my experience with this office. Extremely unprofessional.

Can your insurance cancel your plan because you have unpaid bills to medical providers? Second, are they allowed to threaten their patients in order to collect debts like this?