That is the risk the company faces. I know somebody who is part of ABI's acquisition team, and his specific task is to try to find craft brands that have enough potential to be consolidated into ABI's business and not lose their appeal as a "craft" beer. That's a very tough line to toe, however.
For example, look at how Heineken bought half of Lagunitas a while back... They claim to want to just have half of the economics and let Lagunitas run itself as it would have... yeah, right, and the end result is consumers will be less likely to view Lagunitas as a craft beer from now on.
This happens all of the time in retail banking. Through mergers and acquisitions, a bank gets beg enough that individual depositors say "screw this, I don't like paying fees for everything and not personally knowing my branch managers anymore!" A new bank pops up that is local and promises better service. Time passes, and the big bank acquires the little guy. Start the process over. This is how I suspect craft brewing is going to go as well.