Deployed uses outside of core:
[x] Wikibase `RepoHooks::onPageHistoryLineEnding`
[] Thanks `ThanksHooks::insertThankLink` - handler for two hooks that will need to be replaced
In core:
[x] HistoryPager - https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/593620/
[x] DifferenceEngine - https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/593272/
[x] `Article::showDeletedRevisionHeader` - https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/593826/
[x] RevDelRevisionItem - https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/593620/
[x] `RevisionItem::isDeleted` - https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/593620/
[x] `SpecialMergeHistory::formatRevisionRow` - https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/593620/
[x] SpecialUndelete - https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/593620/
[x] `DeletedContribsPager::formatRevisionRow` - https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/593620/
In core tests: RevisionDbTest, RevisionTest