Question on slots

I am playing on XIGUAN server, and I notice that the slots are only half of the OTTO server, but some big airports already show some signs of slot congestion. Do you know why XIGUAN only has half of OTTO slots? Will there be more slots added to XIGUAN?

Xiguan only has half the slots of Otto because Otto, being a bit of an entry-level gameworld, has twice as many slots as every other server. And no, the number of slots will remain constant. However, after a while the number of airlines will usually decrease, freeing up resources again.