Will you be able to group Cross Server for instances and BGs?
I dont recall if these was a thing in TBC.
Probably not.
Cross realm instanced PVP queuing was implemented sometime during Wrath Season 5, I believe. I do not recall being able to queue instances cross-realm until P2 of Cata Classic with the troll dungeons (and only those), which I assumed was a side-effect, rather than a feature.
