"Delete prior revisions" doesn't work if site builder uses "Account administration pages"

Problem/Motivation

Before installing this module I had my site set up to show the administration interface always in the same language using the language detection option "Account administration pages". After installing this module, whatever I tried I never got the list of prior revisions to delete as well. Until I enabled Xdebug and noticed that "$langcode" in the function "getPreviousRevisions" was getting the wrong current language.
It took a while to figure out why until I disabled that language detection option.

Now I'm not sure: is this a "node_revision_delete" bug or a core bug because one would expect when using languageManager->getCurrentLanguage() you would actually get the language set in the URL and not the current interface language (which can be manipulated by that language detection method "Account administration pages").

Steps to reproduce

1. Install site using languages and translations. Install at least one extra language.
2. Activate the language detection feature "Account administration pages" and make sure it's positioned at the top of the list. Also this language detection only works if you also set the preferred language in the user profile.
3. Create a node with several revisions
4. Install this module and try to delete a revision which has older revisions as well.
5. Notice it will not display the details box with prior revisions to delete.

Proposed resolution

TBD: fix module or move issue to core issue queue

Remaining tasks

User interface changes

API changes

Data model changes