Here is what we learned on our last cruise (10/26 Magic). WHen someone requests a server, they move the server to the table and rotation already assigned to the guest. And if you get on board, and then you go to Sessions and request a server, they can still move that server.
They simply take the server from his/her team, and switch them with the server already assigned to that table. For this past cruise, we had a team who never worked together before becasue someone had requested the server who normally went with our table and rotation.
A little organizational background - There are three teams. Paris, LA and ORlando. These are the three restaraunt rotations. So, when someone is requested, they simply take the person from that table/team and move switch them. Then at the end of the week, they go back to their normal table/team.
I hope this makes sense. So, to answer your question, you can get a server you request, they simply move the server to your table's team.
We are torn between doing this next time and getting to know new people. But our team this time was so great, we could hardly cruise without them again!!! Depesh and Istvan were the best and they had never even worked together!!!!!
P.S. When you make your ressies for Palos, you can also request a specific server. We couldn't even think of dining in Palos without asking for Salvatore!!!