There's a proposal posted by @Yair rand on Phabricator said the sitename of this site should be changed. The use of "MediaWiki" for SITENAME could be confusing. (For example, the search box placeholder text on Mediawiki.org currently says "Search MediaWiki" rather than "Search MediaWiki.org".) Of course such change needs a community discussion, so I start one here.
Topic on Project:Village Pump
I think this is a bad proposal, and we should leave it as-is.
I don't have a strong opinion on either way, but I think it would make more sense to use "MediaWiki.org" than a plain "MediaWiki", since a lot of pages (if not all) on this wiki that self-references it already use "MediaWiki.org" instead of "MediaWiki". example search.
The site name MediaWiki is disallowed during the installation but could be bypassed by changing $wsSitename on [[Special:MyLanguage/Manual:LocalSettings.php|LocalSettings.php.