Thx all for your kind answers, where I haven't been too kind for this forum audience myself. I won't comment on the likes though.
I don't fully agree. The marketing train started with a bunch of 1h videos of people that played the game for 3h telling about the concepts and their experiences. That's much more than we ever had for as long as I can remember. Plus many of the concepts we know about have only been teased (e.g., unlocks) or shown in a proof-of-concept way, without actually being shown in the game and how it plays (e.g., crises, trade, diplomacy). This leaves us in a state where we know a lot about basic stuff but still have a lot to speculate about.
Problem is I don't see a lot of topics talking about what you mention. There might be room for speculation, but again, what for ? (beside leaders/civs blablabla) We know what we know, and we don't know what we don't know. Nobody has a clue of how such a game will play. Maybe not even developers, even if I might be wrong (one example from Civ1 comes in mind : the "all AIs declare war past a point if you are dominant", which was abandoned with patches or Civ2, because psychologically it was a core mess for the player, even if I don't think it couldn't be something now again, at least for best players - but they probably wouldn't care too much ? Well except for trade and economy I suppose). For example, what we call the "meta", it is to say a layer of understanding that encompasses the globality of the mechanics in order to achieve victory (possibly easy), seems to me a thing of gamers rather than developers. An example of this is the Civ3 ICS, for those who remind : the devs explicitly said that they didn't want the game to be played like that (for reasons they probably considered as "exploits"), and made sure it wasn't reproducible in other iterations. (no more "city self destruction" in Civ4 (?), + minimum distance between cities in Civ5 and Civ6)
So what to speculate on ? What will be the exploits, if there is any ? In what ways to achieve an amazing "yield porn", if it can be done ? Nobody can even speculate on this based on what we know. We'll be able to only after a while the game released, because the devs obviously don't want to say too much to not spoil us. I think I've done this error with Civ6, I watched youtube videos before actually playing, maybe ? It is to say that I wasn't quite interested by it, because the graphics were poor in my opinion. With 7, it's quite different, I enjoy graphics, I feel they are a step in the right direction. (I wonder how it can run on the Nintendo Switch 1 though, maybe it is just art style after all) I will not do the same error twice. A good chunk of the enjoyment I have from games in general is being able to crack them myself. If I need to look at a solution, it generally means I will rate them bad. As of now, I still really wonder how some players can beat Civ6 Deity EVERYTIME, while I did it only once or twice. Maybe I was in a good mood, clear mind and all. Or I was simply lucky. (considering the rate fail/win, it's totally believable) Anyway i didn't find good receipes on the internet, and to be frank, i didn't look too much. (lack of interest to be helped and reproduce the things - well, not totally, it's just that I fail most of the time to understand it within a "standard" game, for example I fail to see how work ethics can be so good when surrounded by open terrain...)
I guess what I mention is just post-release stuff. And, judging by the number of posts here, it might be overcrowded at first. Obviously, there will be the "Civ7 is actually a terrible game" threads and all the controversy, and its opposite, like with Civ6. All that to say that unlocks, crises, trade, diplomacy haven't been that much discussed because it's still within the realm of devs. As to 1 hour videos, who wants to inflict that on oneself ? I don't even understand oral english ! I saw some guys in front of each others saying things i didn't understand, with no screen-helper most of the time. Nah, I definitely abandoned the idea of watching those.