For me the issue is not that you discussed the thread, but rather that there are bigger threads with more views and community involvement that could be worthy of discussion. If it's expansion civilization ideas you're after, there's the
Design-your-own-Civ (stickied) thread from the Ideas and Suggestions subforum, with 48,266 views since August 2016, and over 26 pages of contributions and discussion of numerous contributors' ideas. You could pick and choose your favorites from a mechanical/strategic point of view.
Re: the game as is, I think some Polycast discussion of the scenarios would be great (including strategies for some of the more challenging ones like the Alexander the Great scenario, which is tough on Deity), as would discussion on how religious victory has changed in light of the Khmer, etc. I would specifically request a detailed strategy guide on how to properly place districts (i.e. are the adjacency bonuses worthwhile; are there ways to plan them in advance; what buildings spread bonuses to cities within 6 tiles and which don't) would be great. I still struggle with visualizing districts in advance since I don't always know how worthwhile adjacency bonuses are, and how city growth can be bolstered to allow for more district construction (cities with growth bonuses like the Khmer, or say Germany with the +1 district over the limit bonus tend to do better there).
Also, a discussion of war weariness (how quickly does it accumulate when in wars with multiple other civs for example) would be great.
Certainly I recognize that Polycast panelists will have preferences on what to speak about, but if it's strategy discussion we're after I think there's still a lot of ground to cover. Maybe civ-specific features or strategies would be nice, i.e. highlighting each victory type and which civs are strong for it (and how they go about seeking that victory, especially in light of opposition from other civs, difficulty levels, etc).