Arturo wasn't around at the time but I've done some digging and found some of the original discussion along with a public summary on the predecessor of this list: https://lists.wikimedia.org/pipermail/labs-l/2015-February/003399.html

On Sat, 29 Sep 2018 at 19:13, Pine W <wiki.pine@gmail.com> wrote:
Hi Arturo,

Out of curiosity, why was Debian chosen as the sole flavor of Linux to offer? I see the reference to that decision on the page that you linked, but not an an explanation of that decision.

Thanks!



On Fri, Sep 28, 2018 at 9:34 AM Arturo Borrero Gonzalez <aborrero@wikimedia.org> wrote:
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 foundĀ  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.

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