Personally, I think that those that manually transferred should get to keep the names they already have on the destination server. There needs to be a reward for doing so willingly. Also, it isn't fair if players that already had to change their name when they manually transferred have to change it again, even though they remain on the same destination server.
It is unclear, here is what the FAQ says
In the High population test server names were granted by age of character (or so it appeared), but that wasn't not a consolidation of existing servers, so it is hard to know how it will work out in the end. Given the huge number of servers being consolidated, names are going to become a scarce commodity.