I get the impression that atm they just want people to re-roll onto less busy servers. If you look at the blue post for the latest two new servers it seems to indicate that.
We strongly encourage players who wish to avoid extended queues on crowded PvP realms to plan to move to one of these two new realms. We expect these new realms to have a population base that is easily sufficient to long support a healthy PvP realm community.
Quoted from
They did cover FCM and paid transfers in the Classic AMA, so far I’ve seen no indication we’re getting FCM yet.
Free Realm Transfers
Will you offer free realm transfers if servers get way overpopulated after launch?
Will PAID transfers also be a thing should a server drop heavily in population and a player wishes to move to find more activity or reconvene with friends on another server.