Welcome to the Forums!
Anything is possible with time, effort and money.
The biggest issues that you will encounter is that when your trailer was designed with its prior layout, they fit appliances in where they would be hidden by cabinetry, etc., and made penetrations in the shell. So if your moving the bathroom also results in having to find a different place for the furnace or water heater to live, you will need to patch up the existing shell penetrations and make new ones (this will probably also be true of the black tank vent through the ceiling).
Another issue may just be availability of parts. The typical shower pan/seat arrangement that works in a center bath is a single piece item that has the pan on the floor in front of a wheel well, and then it extends up into a seat that goes up over the wheel well. Inland RV has these on their website, but a poster in a recent thread said they were no longer available. So building out the shower enclosure itself may end up a real exercise in custom fabrication--but you may end up with that challeng if you tried to put the trailer back together as originally laid out as well.