If this is the reason they left - it's not a great idea. Engadget was fairly well regarded before they came on board and quite frankly, after Peter Rojas left it has continued to do quite well. In fact, I'd argue that his next venture - gdgt - hasn't really gained much traction.
Brands are NOT easy to build. The NYTimes will remain the NYTimes, despite the fact that many editors will come and go. I think Engadget is in the same place - a new editorial group will replace the old, and they will be forgotten.