You would like to know if there is a Customization Setting for the Password to expire in 8.7?
If you are using ILLiad Authentication for your patrons, then no, ILLiad does not have an expiration for the password. If you are using LDAP or RemoteAuth Authentication, then your system sets the expiration of passwords by your policy. Also, Librarian accounts never expire. This customization changes in 9.0 where you can set the expiration for ILLiad Authentication and the Librarian passwords can expire. See the 9.0 Release Notes. This customization is for any patron account that has the AuthType of ILLiad regardless of what Authentication you are using as an institution.