It is easy to reply "yes, of course", but looking at the overall list of possible improvements of MediaWiki, I think the Wikimedia movement would prefer the investment of developer time in other areas. These cases are imho too niche from the perspective of writing free encyclopedias, dictionaries, media repositories, etc.
In any case, I wouldn't stop anyone willing to work on these features... but neither would I put the organization of the Summit at the expense of any of these features being implemented in MediaWiki. Wikimedia
Phabricator
is a Wikimedia tool that already provides those features, so...
To, me most of these strike me not so much as mediawiki lacking features as everyone already being on phabricator and wanting to integrate with those people. If you take out the integrate with existing phab content arguments, you are basically left with a bunch of features MediaWiki already has.
-- bawolff