MMORPG would 'Ruin' the Bioshock game ???
Not sure how it would ruin anything as you could still play BS1 and BS2 -- as you can now, and you could ignore the MMORPG. I don't think we will get another Bioshock solo game out of Rapture (ignore the vita whatever and that Infinite fantasy BS).
MMORPGs have to have a certain sized following for the game's genre, and since BS1 sold something like 3 million copies that would be a good starting point. Im not sure what they could do further would do in the same 'Universe' that would add anything interesting (Infinite BS really ISNT the same Universe, and what besides Multiplayer Mayhem could THEY really do in that fantasyland ?). You dont want to lose the whole popular Rapture setting, which would be the draw for many players.
If you read any of these multitude of Wiki postings, the ideas for THIS MMORPG would make it different from the (generally pathetic) swarm of others, and be a proving ground for the next generation of MMORPG games.
The BS1/BS2 game Assets are just a starting point (and saves alot of $$$$ which is real important to game companies) and the game has many more aspects to it than the solo games. Using the Tools, game mechanics, Modular Design, and Server Systems developed for this game, they could start several others of different genres at a fraction of the current cost ( $$$$) that MMORPGs take to develop -- and because they could specialize, they could run them successfully at lower playercounts.