Great dude. Obviously it's not the bible -- no one is saying that it is, or that it's a make or break in either direction. I actually don't really care about the tsl at all. However, many people do care about it (much more than me) and the devs have indicated time and again that they are focused spacing it out well. You saw the summary say that they were taking geographic/cultural representation into consideration, and I recall an at-length discussion before the patches on which civ is more likely to appear based on tsl starting locations, which is why I speculated that it might be one of many contributing factors into some decision making. I do hope Korea is in, though I do worry that they may exhaust high quality Asian civs and have little left for the next expansion. Not saying Korea won't be in. I really do hope all of the civs you listed will be in (over some of the nonsense ones I've seen suggested). I'm just not sure I'd say Korea has more a of a 50% chance of being in this time since I assume their higher priority will be Native American civs, the Mongols, Ottomans, and most likely one or two European civs (as is usually the case), since they literally just added two Asian civs. This leaves little room for anything else.
All I am really wondering is whether anyone knows anything besides the crown being pictured in the video.
Oh boy, I'm new here. very tender. But I really wanted to reply to this and any others having doubts about Korea's inclusion.
https://en.wikipedia.org/wiki/Korean_pagoda

This, to me, was a 100% confirmation of Korea's inclusion in R&F the very second I saw it. Though even without this glaring proof, Korea is ALWAYS included in the first expansion pack, so I really wasn't worried.
To that end, I have to say, based on what we've seen and what we've heard (and what we can assume from the two), that we'll see:
Korea, led by Seondeok (as above, as seen in the trailer, and as can be assumed by looking at past versions of Civ + Korea is definitely getting a woman leader to help balance the double sausage surprise currently going on in East Asia)
Netherlands, led by Wilhelmina (on account of the Dutch resistance portrayed in the trailer-- Wilhelmina was their inspiration. Also high time for some new Dutch meat for once)
Ottomans, led by Mehmed II (everybody is saying they saw the Mongols in the trailer-- those guys looked nothing like Mongols to me)
Mongolia, led by Kublai Khan (Tomyris is already the "Genghis Khan" of Civ VI, so I'm willing to bet dollars to donuts Mongolia's taking a new course this time around)
Byzantium, possibly led by Theodora or Constantine (nothing to go on besides what we've seen in past Civ games, really, though there were gladiators in the trailer)
Canada, possibly led by Samuel de Champlain (everything else aside, I really feel this would be the only time to add Canada, as R&F's features are absolutely ideal for a Canadian civ. May end up being some kind of pre-order DLC either way. Sam the Champ would help break the English 20th Century mold going on among other post-colonials however)
India, potentially led by Nur Jahan (of all the civs to receive a second leader, I have to go with India, and Nur Jahan is a woman that Firaxis wouldn't want to pass up. This is mostly wishful thinking, I gotta be honest)
The last two or three (assuming Aztec-style post-release DLC) are really up to the wind, as there's really nothing to go off on. The "vanilla" guesses would be the Zulus and the Incas, but that would be too easy. I'm fully expecting the unexpected.