Crossrealm BG's on Frostmourne with coming TOC Patch

Hello There

As far as i understand there is a BG bracket which limits the equipment in this bracket to the equipment, which can currently be obtained on the Frostmourne Progression Server.
If i'm right, then the new patch should be coming in 2 weeks, which increases the gear "limit" to TOC und relentless items.
So does that mean Frostmourne players will face Blackrock starter gear bracket in battleground?

edit: i just realized, the new Patch does not come in 2 weeks but in 6. The question still remains.