Hmm, I don't think they can do that. What about a guildmate who is on vacation and then returns only to find his entire group of friends/guildies transferred to TOFN, yet the only place he can go is Bloodworthy? That would not work.
Perhaps they could give the option of which one to go, but then you'd have to appease every other region somehow, which isn't happening.
I guess you are right, but still they can't force the remaining 3 onto ToFN considering we were the next largest PvP servers under ToFN (Hard to believe I know). When and if our player population stars resubscribing to use their transfers there will be too much headed to ToFN. So just set either Basilisk Droid or Bloodworthy as a destination server.
Plus new players are going to be joining the game with the expansion etc. If Bloodworthy for example is a standard/heavy server and ToFN is full. People will join Bloodworthy to play rather than wait around to join ToFN.