https://trisquel.info/en/trisquel-60-lts-toutatis-has-arrived
"We will also make it easier for volunteers to provide newer versions of extra packages through an optional community-backports repository."
There was a discussion on community supported backports of software a while ago. As far as I am aware, nobody seems to want to support it. Many of us here are not worried about the newer releases of software as freedom is the goal.
That said, you could use PPAs; those that are based on Ubuntu Precise (12.04) should work with Trisquel 6, just be aware that many of these contain non-free software.
