Is every CRL issued by this CA guaranteed to include its revocation, as long as the original certificate would still be valid?
Well, of course nothing is ever guaranteed, but that is at least required from compliant PKIs:
|RFC 5280 section 5
|A complete CRL lists all unexpired certificates, within its scope, that have been revoked for one of the revocation reasons covered by the CRL scope. A full and complete CRL lists all unexpired certificates issued by a CA that have been revoked for any reason.
Actually it must even appear on at least the first CRL thereafter (thanks to dave_thompson_085):
|RFC 5280 section 3.3
|An entry MUST NOT be removed from the CRL until it appears on one regularly scheduled CRL issued beyond the revoked certificate's validity period.
Delta CRLs, by definition, only contain differences to their base CRL.
And temporarily suspended certificates only appear on the CRL for the time of their suspension.