Having libraries in a library list does nothing that “gives them authority”. If a user <i>doesn’t have authority</i> to a library in QUSRLIBL and QUSRLIBL is assigned as that user’s library list, then the user will not be able to signon. An authority failure will stop the logon. The user must already have authority to the library in order to signon when the library is part of the user’s library list.
However, <i>if the user has authority</i> to the library, then the authority will be available whether the library is in the library list or not. The only difference is that the library can’t be accessed through the library list. It can still be accessed by name.
Regardless, “production” libraries should not be listed in QUSRLIBL. There is no reason to make libraries automatically available when the libraries contain objects that don’t need to be advertised.
Further, the libraries should have PUBLIC *EXCLUDE which should make them unusable in QUSRLIBL.
But, what as Philpl1jb asked, what is the question?