I downloaded the Event Catalog last week to start filtering, sorting, and searching in Excel; then downloaded an updated version yesterday and noticed that some of the sessions are no longer in the catalog. I expected new events and new sessions to be added, as well as come events filling up, but I wasn't expecting that many events/sessions to disappear from the catalog altogether. Does that happen often? It seems like it would make planning my priorities more difficult and confusing if the things I want to attend are no longer in the catalog after I finish prioritizing them.
It's fairly common as you can see here.
Alec Usticke, Fans of Gen Con Facebook Group
Yes, not common but happens. It is also possible for the events deleted to be re-added later.
If the number of events are on line with last year we are still missing about 3000.