? Replacing a link in he sidebar still would leave the MediaWiki lists mentioned one click away, right?
I think the problem is of perspective. You seem to be seeing this problem from the point of view of an experienced MediaWiki user knowing what you are looking for and happy to jump seamlessly to different websites within the Wikimedia family e.g. Meta.
Now look at the same situation from the point of view of someone new at mediawiki.org willing to learn more. This user will probably find Communication, where mediawiki-l is proposed, or will find Mailing lists directly where two more lists are listed. The user might see the "Interwiki redirect - This page can be found at..." and understand or not what it means, feel compelled to click or just go for another mediawiki.org tab open. If that user clicks, will land in a very different context and she might oe might not be happy about it.
Again, for a user sure about what she is looking for all this is no big deal, but probably many users have a mild interest, little time and plenty of new data in front of their noses when they dive for the first time to mediawiki.org.
Can you please comment on the lists mentioned above? Especially wikitech-l, which is in fact the list where most MediaWiki action happens and where there is a good balance between MediaWiki and Wikimedia tech topics. I think it is our interest to promote that list to mediawiki.org newcomers. About the other two, I still think they are purely MediaWiki centric and could be listed here, instead of sending MediaWiki 3rd party users to no less than Meta.
This post was posted by Qgil-WMF, but signed as Qgil.