So I called again and when I asked if I could request to have a seat released as a platinum member, he initially said “When redeeming seats it’s a matter for there to be availability, not for platinum members to request it. But let me put you on hold and check this”
After a much longer wait (than the last call) he came back and said he would have to check availability and if there were empty seats then he could put in the request.
So yes sounds like the first one didn’t want to try but then this guy was kind of reluctant as well.