Linux Mint 18.2 Ubuntu-based OS is Named 'Sonya' (betanews.com)
Brian Fagioli, writing for BetaNews: The uncertainty about Ubuntu has not deterred the Linux Mint team, however, as they are moving ahead with plans for version 18.2. While details about the upcoming version of the operating system are scarce, we have learned two important details. First, the code name for the OS will be 'Sonya,' and second, the distro will use LightDM as default display manager.
You are apparently using that phrase working from the ridiculous assumption that I know what you are talking about. Well, I don't. What is this "uncertainty about Ubuntu" you speak of?
It's a direct quote from the linked article without the preceding paragraph or further links, so poor submission/editing. In short:
1. Convergence: Dead
2. Mir: Dead
3. Unity: Dead
In terms of "why wouldn't Mint continue to be based on Debian", I don't see the big deal though. They go Gnome3/Wayland, Mint will continue to do their Cinnamon thing, don't see there's any uncertainty about Ubuntu continuing to exist as an okay base for other distros.
Live today, because you never know what tomorrow brings