I received the same thing. I couldn't hear them very well. It seemed like there was interference on the line, so I told them to call back. I had a funny feeling about this. It could be legit. I have had them call be before following hospitalization. I have put a query in to UnitedHealthcare and will update once I get their response.
The caller ID for 1 763-219-4272 just said "Minnesota." The recording didn't leave a name, but left similar instructions to what you list: Name, spelling of last name, DOB, and phone number.