Just in case it is useful to someone else:
A few days ago I felt motivated to try out Trisquel 7 again.
This time I tried to do what was suggested in
http://trisquel.info/en/forum/trisquel-70-flash-disk-and-amd-raedonlimited-resolution:
Commenting the line in /etc/modprobe.d/disable-radeon.conf, run 'sudo
update-initramfs -u' and reboot the system. It didn't appear make any
difference. But that's not very unexpected either because
/etc/modprobe.d/disable-radeon.conf is present on Trisquel 6 as well, with
the same contents.
So, the clear things up a bit: It seems like radeon has always been
blacklisted for me, both on Trisquel 6 and 7.
In Trisquel 7, I now know for sure that xserver-xorg-video-vesa is being
used. I have tried to remove other video driver packages and have not been
able to see any difference. By removing xserver-xorg-video-vesa, though, I
get no graphical interface after rebooting.
Trisquel 6 and 7 uses different versions of that package:
Trisquel 6: 1:2.3.0-7build2
Trisquel 7: 1:2.3.3-1build1
I tried downloading the Trisquel 6 .deb file and install, but that
unsurprisingly didn't work very well. dpkg complained about unmet
dependencies. After a reboot I got no graphical interface.
My current idea is to try to recompile the Trisquel 6 version for Trisquel 7.
