I agree with the point that SE should wait until after billing to evaluate server mergers. Personally, I'd even like them to hold off until after 1.21, because even if players aren't going to stick around now, the introduction of jobs could generate a lot of interest simply because of the nostalgia attached to the names.

After that point I think it's feasible to evaluate which is the best option, even offering a one-time transfer to the more empty servers could help the problem, that way players would have the ability to choose where they head (potentially meeting up with old friends they were separated from at launch) instead of being forced into a server merge.