state disability review by phone call?

Social Security (a FEDERAL agency not a state agency) does it often. It's a more efficient way of conducting the medical reviews mandated by Congress.

If a person is set up for reviews every 7 years it's just a routine they have to go through - and frankly a waste of time but because Congress mandates these reviews for everyone - social security spends as little time as they can on people whose disabilities are so severe that they are only reviewed every 7 years. They have to go through the motions.

If a person is set up for reviews every 3 years or less then it just means that that particular claims rep is very efficient. The form will be completed correctly and is mailed out for signature and returned. Overall it saves the agency time and the beneficiary since the beneficiary doesn't have to go into the office or stress out about having a form to complete themselves.

If you truly receive benefits from the state I have no idea what it means when they do it over the phone.

Depends what type of verification or documentation may be required.