Paul,
I have heard the same regarding ZLY, but didn't know ZRX was going too.
Although Rex has 13 B+ models in the fleet the older B+ is not a WT model as classified by the company. It does have the newer interior with the larger overhead lockers and the more streamlined window surrounds etc, however it does not have the extended wingtips. I'm sure it has a lot of other differences in the flight deck.. but don't ask me what they are!
David.M.