You correctly point out that Ubuntu is a stable, non- "rolling release" distribution, so it will always require some "tweaking" to get the latest-and-greatest software. That's just the nature of the beast. If Xorg Edgers team hasn't added 1.19 yet, then I wonder why not? Did you notice any comments on their website or mailing list to explain the delay? They are experts on the topic of "latest xorg in Ubuntu" so I'd follow their advice over some random guy on the internet named snowpine, quite frankly.
If bleeding-edge software neatly packaged in the repositories with no "tweaking" is your goal, you might consider test-driving a newer release, such as Fedora 25 (released Nov 2016) or Debian Unstable (constantly "rolling" with the latest software).
Or, another suggestion, maybe take a step back from the problem and look at the bigger picture? You could start a new discussion thread with a title like "Screen tearing with Ubuntu 16.04 and Nvidia XYZ?" replacing the 'XYZ' with the actual chipset of your hardware. (Use 'lspci | grep NVIDIA' if you aren't sure exactly what you have.) Maybe there are other LinuxQuestions users with Nvidia cards, who have found an easier solution that doesn't require lots of tweaking. You won't know unless you ask.
