From the trip reports I read - someone recently asked for an upgrade at embarkation in Galveston. They were told no, check with guest services on board. Once on board - guest services told them they would text them if possible. They found out a couple hours later it was not possible.
On Dec 17 - I asked about an upgrade at embarkation and was told "no." I was not surprised. I think our sailing of the Wonder probably the most passengers on that ship since COVID. That is based on the state room category availability over time. The two weeks prior to our sailing had many more rooms available. And of course this week's Christmas cruise is probably even more occupied. But the weeks in January are offering 30% off.