There is no warning when modifying or deleting mandatory classes of XWiki

When modifying a page from the wiki which is part of an extension (depending on the type of that page in the extension descriptor) there is a warning that tells the user that some unexpected stuff may happen and asks them to force the editing, like this (example for the XWiki.XWikiSyntax page):

When doing the same for a page that is a mandatory class which is initialized by XWiki upon start and re-set everytime when the wiki starts, there is no message at all.
To reproduce, you can try to edit the page XWiki.XWikiComments and there will be no message.

Expected result:
For these mandatory classes, there are actually 2 things that the user that makes the modification should be aware of:

• if a user changes them, things may not work as intended anymore - like for the extension pages
• (some of) those changes are not persisted: will be reset next time the class is used or next time the wiki is restarted - see, for example, XWIKI-18854 .