This is no more apparent than when an update appears on AOSP and brings with it thousands of changes. In fact, this update is large enough it probably deserved more than a barely noticeable revision bump.
There is indeed the possibility that Google releases a new version of Lollipop before the launch of Android M, probably to accommodate the various bugs still scattered in the code, and build it just seems to confirm with the large number of commits, about 3,000, that accompany it.
Just to put a little 'things in perspective, the word "fix" appears 438 times and at the moment have not been found special new features worthy of note, but there are also some references to Doze , just to confirm that Google is preparing pavement for Android M.
However, you can comb through the entire changelog looking for something new, but it is said that this build will result in a release to the general public, especially since it is quite antiquated (about a month), although, as mentioned above, we expect a new OTA Lollipop arrivals before Android M. (Muffin? Marshmallow? Morositas? Mojito? Mortadella?). Source : Android Police
