For namecheap domains with WHOIS privacy: If you let your domain expire, your contact information becomes publicly available. This is even though you no longer own the domain. You then have to contact them, and as a “special” exception, they will change the contact information to their own reactivation contact details.
This is incredibly unfortunate on the part of namecheap. The only workaround I know if is to put in bogus WHOIS contact information the day before the domains expire.