TESVI will require the writers and designers to think of stories and new game mechanics that will top TESV:Skyrim in order for fans to be happy (an opinion)
Maybe I have the perspective mentioned in the title because there hasn't been much rumor or leak other than that BGS has TESVI in "pre-development"? and the province of focus might be Hammerfell.
But from playing Skyrim, BGS added some over-the-top stories, quests, and game mechanics that I fear BGS might not be able to top in the 6th game.
Just looking to read your opinions and feedback.