In theory, the problem could also greatly be on not just the particular world's server, but ALSO on the cross-server instance system. Remember how at the earliest portion of the crashy release the big problem was getting 90000->3104 combo and being stuck there into infinity once you hit an instance. Yet you could zone properly.
This seems to indicate it's not the world server ITSELF that is being problematic, but the cross-server instances can't handle the stress, so they need to limit the number of people in worlds, which is the only place wherein they can limit the number of people, to avoid the instance server getting overwhelmed.

Which means that the addition of new worlds combined with the sub-sector structure they are adding to the duty finder/instace server (don't track ALL servers i nthe cluster only a few paired ones) means that the root problem, the instance server, will likely be gone and they can alleviate logins.

That said it would be a big QoL thing if they could implement a proper queue system, for some reason people aren't as angry at not playing for the entire day as long as there is a screen saying "Position in queue: 521478" for 24 hours, yet are raging when they need to keep pressing X/0.