Gold status has no impact on the Contract of Carriage terms relative to checked bags you agreed to when you purchased the ticket. Granted, most people don't bother to read it, but that certainly is not UA's fault:

"UA shall not be liable for loss of or damage to protruding parts such as wheels, feet, external pockets, pull and extending handles, hanger hooks, external locks, pull straps and security straps."

UA has the right to deny your claim as compensation is clearly not due, but you can try anyway.