Maybe at some point, but this is just updating the kernel itself, not the system Google distributes as Android. That basically means the stuff that the Android developers have created to make Linux run on Android devices is being added to the mainline kernel. In other words, for the first time, you should be able to compile the mainline Linux kernel and boot it on an Android device.
udev related? I'm having an udev issue on my Thinkpad T420s where udev doesn't detect the trackpoint if the touchpad is enabled in BIOS. The people that work on udev must have very little hair on their heads, I can only begin to imagine the frustrations of incompabilities and bugs they have to deal with.
The Linux release cycle has been essentially stable with time-based releases 2-3 months apart for the past 8 years or so. So this shouldn't be all that surprising.
They changed the numbering with the version 3 so while you are right, indygreg has a point too. We've lived with 2.6 for years and now they change the second most significant version pretty often. I've no feelings about it, just saying.
But that has no actual effect whatsoever, and absolutely shouldn't have any difference as to whether you use the kernel or not.
IMHO, they could have just as well dropped the 3. and just use a single integer to denominate new versions. What difference does it make whether it's kernel 3.3 or kernel 6?