Trouble's a-brewin Mythic opened up free character transfers from yet another of its Warhammer Online servers. What this move indicates is that another one of their servers will be closed, hence the merger.
If you're on the Ostermark server, you have the choice of moving to the other RP destination, Phoenix Throne, or the Core server Vortex, in case there are conflicts with existing characters on that realm. But do note that the Core server Vortex can only be chosen for a limited time.
Mythic did not actually state that a server will be closing, though, so this could just be one of the regular transfers. Or not.
For more information on the servers and the corresponding transfers, check out the link below.