When TimedMediaHandler has been enabled on all wikis, TimedText namespace was also added to all of them.
The rationale is that wikis might want to upload audio or video files locally and add subtitles to them. However, most wikis are not interested in this and indeed it's very seldom a good idea to to do so.
Moreover, this is surely not valid for the wikis which have local upload disabled and won't want this additional interface clutter.
So, what needs doing:
- Disable the namespace on all wikis with wgEnableUpload false or "'upload' => true" only for sysops in groupOverrides in https://noc.wikimedia.org/conf/highlight.php?file=InitialiseSettings.php
- (IMHO) Just disable it on all wikis and make it opt-in (except for projects like en.wiki which already expressed interest/used it).
- Whatever the conclusion, inform all wikis on what the new namespace is and what they can do about it.