I have found them to be very knowledgeable and helpful whenever I have called Medicare, so it's worth spending a little time on the phone. It may boil down to whether or not they take into consideration this new level of care. I found this link to Medicare's website to be helpful as well:
https://www.medicare.gov/coverage/telehealth
They specifically say you can get coverage for a doctor that is out of state.
The link below is helpful as well-
https://www.cms.gov/newsroom/fact-sheets/medicare-telemedicine-health-care-provider-fact-sheet

Medicare definitely pays for telehealth. Traditional Medicare does - I am not sure about Medicare Advantage plans.
Out of state depends on the license of the practitioner. I am a mental health professional and I provide telehealth appointments. My license requires the patient to be in the state where I am licensed, but I can be anywhere. So, it depends on the license of the physician.

What is an OP specialist?