Move Fast and Break Nothing
The problem with the new motto is that it is uncontroversial.  As Zuck himself once mentioned at Startup School, corporate mottos are valuable only if they are controversial, that is, "be honest" is not a valuable motto, because it is obvious and uncontroversial, whereas "Move Fast and Break Things" is not so: it says something about prioritization that not everyone agrees with, and thereby communicates where the company stands on this issue.  Everyone wants to move fast as long as nothing gets broken.  I agree that it is possible to leverage technology to move faster while keeping things less broken, but it does not change the fundamental dynamic that at some point, you will have to trade _some_ stability for speed, and the new motto does not take a stance on which one it prefers at all.