I am all for speeding up the game as i don't have 3.5 hours. The only way that i want to see it done is by keeping managers / pitching coaches in the dugout. I don't want to see the manager waste minutes every other inning by going out there after every close play and talking to the umpire wasting time until they get a look at the review. I think that if you limit the amount of times a catcher can go talk to his pitcher to once per inning and limit the number of times a pitching coach can come out and talk to a pitcher to once or twice a game. This is how you speed up the game without really changing it too much.
As far as I am concerned there will be enough of an uproar if they were seriously considering banning shifts that it would not happen and just judging by his interview it didn't sound like something that was very imminent just answering a question asked without completely shutting the door on it.