Do you know something I don't? A few years back, Debian changed their LTS policy to 5 years in response to Ubuntu.
> Debian Long Term Support (LTS) is a project to extend the lifetime of all Debian stable releases to (at least) 5 years. Debian LTS is not handled by the Debian security team, but by a separate group of volunteers and companies interested in making it a success.
> Thus the Debian LTS team takes over security maintenance of the various releases once the Debian Security team stops its work.
> Debian Long Term Support (LTS) is a project to extend the lifetime of all Debian stable releases to (at least) 5 years. Debian LTS is not handled by the Debian security team, but by a separate group of volunteers and companies interested in making it a success.
> Thus the Debian LTS team takes over security maintenance of the various releases once the Debian Security team stops its work.
https://wiki.debian.org/LTS