The 1.34.0-wmf.16 version of MediaWiki is no longer blocked[0], and has been deployed to group1 and group2[1] as of 21:23 UTC.
Thanks to andre__, Krinkle, aaron, thcipriani, everyone else who worked on unblocking the train, and everyone who has been so helpful during my first week of train duty.
[0]. https://phabricator.wikimedia.org/T220741 [1]. https://tools.wmflabs.org/versions/
-- Your unassuming train minion
Brennen Bearnes