A wise decision, in my opinion.
I even thought of proposing just that, in the previous discussions that I saw
being held here. But refrained myself from doing so, because, not only am I
not part of the developing team, but also, because I'm still waiting for
Trisquel 6 to be released (exactly because it is based on a LTS version of
Ubuntu) I'm still not sure if I will adopt this distribution or not.
I've been a long time Ubuntu user, almost since that distribution appeared.
And, through the years, I've repeatedly had so many bad experiences with
non-LTS versions, that I don't recommend any of those to anyone any more. And
will only use one if I really have to.
Non-LTS versions of Ubuntu are often buggy and, definitely, not as stable as
the LTS versions... (And I think there's also no need for them. Since, 2
years is, to me, a decent time interval to wait for a new version of an OS.)
To base a version of Trisquel in one of those non-LTS versions is to be
inheriting all of those bugs and to be possibly wasting a lot of time trying
to solve them, which can be spared and better used if you just concentrate
yourselves on the more stable LTS versions.
I've always thought that it is best to do little, but well done, than to do
much, and badly (or not as well) done.