Basically, buy game for $60. No sub fee. Three months later "Content Pack A" comes out. New Areas, skills and quests for $35. Three months later "Content Pack B" is released for $35 and so on.
Buying the content packs is purely optional.
What Zenimax could even do is have a season pass where one would get three content packs for $90.
Essentially it will be the same model of buying a game and DLC for it every three months. If you don't want the DLC, you can still play the base game. This is a method that console players would understand and keep them playing and paying for the game.
I’m at a time in my life where I only play a game one or two hours a day and only a few days a week. A game that requires me to pay a monthly fee feels to me like I’m being cheated. I'm not getting my money's worth. Frankly I want to play a game on my schedule. Basically let me take as long as I want to finish up the content I paid for, and when I’m ready I’ll buy the new stuff.
Could you imagine deciding to play Skyrim again after taking a break for a while, wanting to make a new character and being asked to pay $15? That is how I view games with a sub fee. But I’d gladly pay $30 for new Skyrim content every six months.