Not all of our desiderata for T248186: Prepare Parsoid for MediaWiki 1.35 LTS got done, and we've found some other things that should get done before the next release.
This is a parent task for everything Parsoid-related targeted for 1.36 1.37 1.38. (Often this is because we want to ensure things get deprecated before release so we can then remove them in a future release and clear them as blockers for integrating Parsoid in core.)