It looks like Mediawiki 1.31 has been out for a few months. Any idea when it will be available via Installatron? I know it requires PHP 7, so perhaps that is part of the delay?
Updating versions of applications is in the hands of Installatron, so often when they fall behind a gentle nudge helps to get a timeline. I can do that for MediaWiki and try and give you a sense—but unfortunately it’s a bit out of our hands.