I'm long past agnosticism on Civ VI.
I think they may have planned some kind of 'additional content' package - maybe not a complete third expansion with a half-dozen new Civs and bells and whistles, but Something.
But now, the Civ franchise is facing some major competition in its own sphere of Historical 4X for the first time in years and years. Not just Humankind, but Soren Johnson's Ten Crowns (which called for Alpha Testers in November, so is definitely in development after two years of near-total silence) and the new Settlers game from UbiSoft, which looks suspiciously like, at least, a Colonization-type game and may include enough Civ-Building features to compete directly with Civ.
All that is enough to make anyone reconsider their development path: there is no sense in bringing out a third expansion for a game that is considered passe' or second-tier compared to its newer competition.
There may be something still in the 'pipeline' that will get shoved out, but I wouldn't bet on an Expansion: more like a (maybe) fat DLC at best.
On the other hand, I'd bet that Civ VII development has had a kick in the kazoo as a result of the sudden increase in competition looming up next year. AND I'd bet that there is a lot more consideration being given to massive changes in the way Civ does things as a result of different mechanisms being shown or speculated about in the competition - and commented on in former 'Civ-Only' Forums like this one.