In TESO (mmo) you will be able to adventure and see all of Tamriel, all the provinces you've never set foot before the singleplayer games.

Don't you think that this will destroy the exploration and the feeling of a new land in the next ES RPG? Lets say the next ES game will be set in Black Marsh , your gonna see it in the elder scrolls online and then when ES 6 launches you already know how Black Marsh looks ingame.

Im excited about a ES mmo but I also fear that it will destroy the next ES RPG games after Skyrim.

What do you guys think?

I have no such fear. I'm not going to play TESO, so nothing will be spoiled

I'm still trying to grasp that horrible decision as well OP. Now I see no future for TES: Black Marsh.