Other than being engaged by Canonical, is there a reason the Snap platform be preferable to the Flatpak one?
I totally understand the frustration of developers wanting to release on Linux and balking at the faff of adding your app to ~n package managers, but AppImage seems to be the wrong solution to that problem.
Snaps are quite nice though, from my experience so far. I've found the documentation a bit lacking, though it is improving.
EDIT: I got confused thinking FlatPak == AppImage, so you can ignore most of the above! I'm gonna check out the FlatPak system, looks interesting.