I disagree with this. You can keep the server and just lock it so no new character can be created on it, I think everyone should be auto transferred to the other server though. No point in keeping half a population on the least populated server out of the three. I mean the PVP server stands to gain the most out of this merger really, it's the least populated by far.
Sorry i should have been more clear.
The PvE server and the PvP server remain important too so many people where the PvE people shouldn't be forced onto a server where they are vulnerable to being ganked whereas the PvPers can simply toggle the PvP option and continue to what they are used too so I agree that the PvP server should be locked until the numbers are there to fill both servers. But this is only an option to the PvP server members should they be happy with the positives of a server merge compared to the negatives.