Actually LTS does break ABI, but gregkh is working with Android to make a partially ABI-stable LTS (I assume it would be a fork of the real LTS though?).

I know they are also working with RH and Suse, but I don't know if RH and Suse will only share the tools, or will also have the same LTS source tree.

When I say "partially-ABI" stable, their goal is to list acceptable symbols and automatically verify that vendor modules use those symbols, and only those accceptable symbols are ABI-stable.