Yeah, 2K is really shooting themselves in the foot with this old school marketing strategy, in my opinion.
They really should just come out and confirm (officially, not obliquely on a stream 9 months ago) that more Civ 6 content is in development. They don’t need to say what it is or what it will look like, just something, given that we are in uncharted territory.
Because another thing that just occurred to me is that most casual players almost certainly assume Civ 6 is done because it’s gotten two expansions. (I’ve literally heard this said on a gaming podcast I listen to, and the hosts are in the industry and they think this—because they aren’t Civ Fanatics!)
So they are kind of running the risk that if they wait too long, more content will drop and people will have lost interest and moved on to other things. Now I’m sure the Civ brand name counts for a lot here—a third XP would get a lot of press of course—but it’s still something to consider.
In any case, I don’t think it’s entitlement to just want some form of confirmation that stuff is coming. You’re not saying you want it tomorrow or that it needs to be X thing, just that you would like to know if more content will come.