Yeah. https://worldofwarcraft.com/en-us/news/23090136
Q: Will there be Cross Realm Battlegrounds when those go live?
A: Cross-realm battlegrounds were a feature of 1.12 and are important for matchmaking, so you’ll be seeing cross-realm battlegrounds in WoW Classic when Battlegrounds are introduced in Phase 3 of the content roll-out plan.
While I think ally will have lower average que times than horde, I doubt it will be by much. Also pretty unlikely ally will have insta bg ques. Blizz will probably gerrymander the battle grps to make it closer to being an even H/A split. I could be wrong, and I actually hope I am wrong- but I don’t see why they would implement cross-realm bgs if they weren’t trying to even out the bg wait times for both factions. I’m staying on Herod either way.