I assume you have read the "New Efforts" thread under Task Force Hail Mary. If not, go do that. I'll wait.
(several hours pass)
OK, the hardware is not the issue. The servers are virtual. There is no additional cost to have them all back.
Since it doesn't save any money to not have them (they are virtual servers, not physical ones) all, why not? It will avoid the problem with duplicate names at relaunch which is going to be a problem if you merge at launch as you won't know who is active and who is not. Once the game is up i could see them merging low population servers, but by then active players will be able to prepare for the merge. Non-active accounts can be cleared to reduce the conflicts and free up names.
It will also be quicker and easy to relaunch the fewer changes you make.