It's a good setting, I watched some Elder Scrolls online videos of it. I like the architecture and the environments. It's the homeland of the Bretons and the Orcs. The Bretons are an interesting race, as they have some Elven blood and therefore are the best of all the Human races at Magic. As such,  there are multuiple Mages Guilds locations in High Rock. The Adamantine Tower stands on an island in a bay in High Rock, the oldest structure in Tamriel, it was already standing when the elves came to Tamriel, according to myth it was the meeting place of the Aedra (Gods) when they decided the fate of Nirn (the planet Elder Scrolls is set on).

I think the setting will be even better if they combine High Rock and Hammerfell, that would be really cool.

Yeah, his evidence is compelling for sure, Hammerfell feels almost certain at this point. Funny thing is, after watching his video, I remembered that I predicted Hammerfell would be next right after playing Skyrim the first time in 2011. The fact that the Aldmeri and Hammerfell fought a war just a few years before TES 5 is what I based that prediction on at the time, the Thalmor perfectly engineered the White-Gold Concordat to alienate Hammerfell and stir up hate between Hammerfell and the Empire so that Hammerfell wouldn't call for Imperial help when the Aldmeri Dominion invaded Hammerfell. But Hammerfell surprised them, they put aside the Civil War between the Forbears and the Crowns and banded together to fight the Dominion, and so skilled are the Redguard of Hammerfell at combat that they managed to hold off the combined Altmer, Bosmer, Khajiit army of the Aldmeri Dominion by themselves for 5 years, fighting to a stalemate that ended in a peace treaty. But the Thalmor are cunning and ruthless. they won't give up taking Hammerfell so easily, as they need to take it before they can move Northward and take High Rock and Skyrim, they will either orchestrate a war between the High Rock and Hammerfell to weaken them both enough so they can take them, similar to the war they orchestrated between the Stormcloaks and the Empire in Skyrim during TES 5, or they will attempt to stir up the Civil War between the Forbears and the Crowns again in order to weaken Hammerfell.

My theory as of now is this. TES 6 will be set not long after TES 5. Will have a combined High Rock + Hammerfell map, and will feature the Thalmor trying to stir up trouble between Hammerfell and High Rock in order to start a war between them and weaken them both enough for the Aldmeri to invade and take them, which would then pave the way into Skyrim so they could take it too, leaving the Empire with nothing but Cyrodil and Morrowind. You will play a part in deciding the outcome of the war in game, similar to how you could decide the outcome of the war between the Stormcloaks and the Empire in TES 5, but a canon ending will be decided between TES 6 and TES 7. That ending will be that High Rock and Hammerfell realized they were being played by the Thalmor and ended the war between them, so that they could face the true threat to the south, the Aldmeri Dominion. Then TES 7 will feature a combined Summerset Isles + Valenwood + Elsweyr map, with that game being about the combined Hammerfell + High Rock forces invading the Almderi Dominion. 

I expect singleplayer with an region for online. Like an arena where you can fight together.