(1) Presently, Users group user can edit user-contributed objects of non-restricted types (T349082). When a user switches to the Edit mode, the warning says: "You are editing the function definition page. Only users with special permissions can change the definition of the function."
Since editing non-restricted objects types is available to all users, the warning is not applicable anymore?

(2) When a user in Users group attempts to edit Core types, the above warning is not displayed:

However, when users (Users group) after making some edits, click on the "Publish" button, the following warning informs them that they are not allowed to save their edits.

Users in Users group should be timely informed that they are not allowed to edit certain objects types.