I sure hope not. A better system would be something like NIX/GUIX or even Gobolinux, that give us a single package as today, but with the option of installing multiple versions in parallel if upstream has screwed up the API (again).
Flatpak and like will just be and excuse for upsteam to bundle everything and the kitchen sink, resulting in bloat and having to update a mass of paks rather than individual libs in case a flaw is found.