It is my understanding that InBev will not be selling any brewing capacity at anytime in any part of the Labatt deal. They will produce beer for three years, then you have to have your own capacity in place.
A reason InBev may at some point ATTEMPT to regain Labatt USA is because they are not selling the entire Labatt company. Just a few miles over the border InBev will still be producing, bottling, distributing, and selling Labatt beer.