Nice list Kilora!
I'm hoping it will be included in 2.4 -- along with 3+ new WZs, new WZ maps, arenas, and an actual start to Season 1. (At least, cross-server for Ranked).
While the exact details of which features will make Game Update 2.4 are still being hardened I can definitely say that Cross-Server Queueing is not in the plan for it. We've taken a hard look at Cross Server Queuing in the past and accomplishing it is a *significant* challenge that would take a lot of time away from other things we are working on. Emphasis on significant. It's not forever off the table but it's not in the plan right now.
Even though it is too early to share specifics I can say that Game Update 2.4 as it is being worked on right now has features and changes that should cause a significant improvement of queue times for ranked Warzones in particular. Emphasis on significant!