Is there a way to restrict users from selecting a particular custom Inventory Status?

I would doubt it

Yes.

Without knowing what you're trying to do, I can think of a few solutions. Replicate the custom status behavior with a hidden checkbox that gets triggered by whatever is currently setting your custom inventory status. Have a client script that displays a message that tells the user it can't do that, then change it back. Hide the actual status field and make a custom status field in the UI that only displays the statuses you want the user to be able to select, disabling it if it's that custom status.

Thanks, sounds good!