Hello Snarkyfork!
They were released sometime after January 2019, thus they are part of the Patreon backer batch libraries including the most up to date releases as well as all the releases after January 2019!
https://aekashics.itch.io/librarium-batch-libraries
$1 pledge tier patrons get access to all previous and current animated & static base releases!
Let me know if you have any further questions!