Cinnamon is/was made only for one distro, Linux Mint, and Linux Mint is still based on Ubuntu and LMDE on Debian. Cinnamon DE would always work with both Ubuntu and Debian, and if it works with Ubuntu, then, it works with Debian unstable – Ubuntu is a tweaked mix of Debian Testing and Unstable, one of the reason, why Linux Mint stating that Ubuntu updates are not safe. That’s why Linux Mint had created a tweaked Synaptic, so not all Ubuntu updates get in and break it.
Linux Mint is quite successful in the Linux world, so would never think of being an Ubuntu flavour. Cinnamon was created, when Ubuntu started with Unity. And, the rest is known.
Just installed today’s Ubuntu 19.04 updates through Linux Mint’s Updater on my Disco-Cinnamon. The Updater is a part of that tweaked Synaptic. Installing apps or updating is through Gdebi or Synaptic, and not through a “software shop” that doesn’t tell you what it is installing. That’s one of the reasons, most Ubuntu users immediately install Synaptic.