Ya it's probably to copy NXL's strategy of mimicing how other main stream professional sports are, the teams are associated with cities.
As for NXL going to NPPL, i know there's rumors but I don't think that's going to happen.
IF they run the NXL and the Pro division with city named teams, it would cause 'consumer confusion'. It's one thing to do it in totally different leagues, but to merg them together and have that would be confusing to non-paintballers. It's rare to have 2 teams of the same sport in the same city. If anything, i think NPPL going to the city names goes against the rumor of NXL moving to NPPL.
I think if NXL leaves the PSP, it'll be to do their own thing.