Repository Question

I'm running Trusty and yesterday updated from build 3.9.2xxx to 4.1 by removing and adding the repository listed on the site.

#deb http://apt.tvheadend.org/unstable trusty main
deb https://dl.bintray.com/tvheadend/ubuntu unstable main

The package that gets installed is a "Precise" one.

tvheadend_4.1~precise_amd64.deb

The package works as far as i can tell but a bit strange when the site does not even mention Precise as supported.

Works with.

Ubuntu 14.04 - 'Trusty'
Ubuntu 14.10 - 'Utopic'
Ubuntu 15.04 - 'Vivid'

Is this to be expected?

Tvheadend