I wonder if this will be just one in a wave of derivative distros rebasing from Ubuntu to Debian? I think doing so has been in the cards as a distinct future possibility for many of them, most overtly so with Mint's LMDE variant - even if it's ostensibly just an alternative, I think it's clear to everyone that it's always been about making sure they have a viable, working alternative, for the day when an Ubuntu base is no longer tenable.
Is anyone aware of whether there have been other distros rebasing from Ubuntu to Debian lately?