Yes it will raise slightly. I keep mine at 10 psi. when not towing when I hookup the trailer with the WD hitch it jumps to just over 15psi. it is a small jump, but because of the load on the bags the pressure will increase. I run mine at 35 psi when leaving and on the road for a trip. and coming home I need to drop it to 20 psi. due to the weight change of the trailers tongue weight. It is nice to be able to dial in the WD hitch with the air bags. I highly doubt you will need to run 50 psi in the bags to level out. if you do you need to readjust your hitch setup.
BTW, I have the Air Lift bags with the Dual gauge setup that I can adjust left and right independently if needed right from the front seat. I don`t need to adjust independently, but I don`t want the air pressure transferring right-left or left to right during turns. it helps with stability more so on a Truck camper and maybe a 5`er, than when your towing a TT.