As long as we're on the same patch, general raid progression doesn't matter. The bg's will be mixed with players from both servers if the crossrealm works like it does on retail.
Viper wrote:Greetings, as stated earlier, transfer won't be possible.
The PvE will not realease on the same Server Patch like the PvP Server! So it's not on the same patch! And I think raid progression does matter because there are seldom full PvP geared people in BGs.