Apparently though there is only a set number of instances that can be active at one time which adds to queue times. If you have more centres then you can have more instances, which in tail either means the same amount of waiting time or if anything potentially shorter.

Average queue time is about to increase as the same pool of players will now be spread across 3 data centers instead of 2.
It's actually not that bad on EU after the split, roughly the same as before anything was changed and we have much less active players than NA.