Calling to attention about that is not anti-canonical trolling. It's avoiding creating a dependence on a third-party.
Source?
Snaps require AppArmor which is used by Ubuntu and openSUSE. This makes it harder to integrate Snaps into Red Had (SELinux) distros, but I wouldn't say that this is something RH does actively to cripple them.
As for all the mentioned package/image managers, IMO they all bring more problems then solutions (except maybe nix). Dependency resolution brings sloppiness and keeping the programs dependencies up to date would kill the internets and hard drives (compared to a normal package manager). They should just build a build bot and amen (or just not do anything). The only "problem" they solve is proprietary program distribution, and that is solved by a Filesystem Hierarchy Standard (and fd.o) compliant installer such as MojoSetup (as used by GoG).
Edit: somebody answered to my doubts in a comment here https://news.ycombinator.com/item?id=13559060