Hi!
We would like to share some information regarding Wikimedia Cloud Services plans for deprecating Ubuntu, specially Trusty.
Ubuntu Trusty's end-of-life is April 2019 and the WMF decided to consolidate in a single operating system, which is Debian.
In Cloud VPS, projects containing Ubuntu virtual machine instances have been contacted by means of a Phabricator task. Toolforge users aren't affected by this right now, because Toolforge itself is currently running Trusty. But we are already working on the next, Debian-based, Toolforge version.
All this information, more details (and timelines), can be found on this Wikitech page:
https://wikitech.wikimedia.org/wiki/News/Trusty_deprecation
Please, let us know any question or doubt you may have.
Best regards.