Hello,
as I understand there is currently ongoing development to create a new renderer for PDF versions of wiki pages.
Development is ongoing since August 2018 according to
https://www.mediawiki.org/wiki/Reading/Web/PDF_Functionality
as I also understand nothing has been deployed on any Wiki yet.
as I also understand the new rendered is based on mwlib.
as I also understand mwlib does not work with Python 3 according to
https://mwlib.readthedocs.io/en/latest/installation.html
It will /not/ work with python versions >= 3 or < 2.6.
as I also understand Python 2 will not receive any security updates from 1st January 2020 according to
https://www.python.org/dev/peps/pep-0373/#update
Being the last of the 2.x series, 2.7 will have an extended period of maintenance. Specifically, 2.7 will receive bugfix support until January 1, 2020. After the last release, 2.7 will receive no support.
as I understand concluding from the above the new renderer will be decommissioned on 1st January 2020
which I don't understand as you will certainly understand.
Yours Dirk