The MediaWiki / Wikimedia developer community is doing poorly at volunteer retention, and there is wide agreement that the difficulty of getting code review is one of the main problems (possibly the main problem) behind this. There has long been interest in improving the situation (e.g. T78768: Agree on and implement actions to prioritize code review of patches submitted by volunteers) but not a lot of concrete actions happened.
One of those was T128371: Set up Code Review office hours, which did not really work out, maybe in part due to lack of organization / effort, but mainly because IRC wasn't a great channel for code review (except for very simple patches). Per T173770#4076361, that effort has been abandoned; let's find a replacement that works better.
The aspect of code review office hours were authors were able to put their patches in a central place to get reviewers' attention was IMO valuable; but then coordinating that everyone be online at the same time was an unnecessary complication, and the poor usability of events in Phabricator made the patches hard to find.
Let's have a code review queue instead: a wiki page or Phab task where people can nominate their patches (and maybe patches by new volunteers get auto-nominated), they get announced to wikitech-l once a week, and patches which get a review are removed from the queue.
Resolved with https://www.mediawiki.org/wiki/Code_review/patch_board