Think for a moment about what it actually means to revoke a private key in X.509 PKI.
Originally, you created a key pair, and you submit the public key to a certificate authority (CA) for key signing in certificate signing request (CSR). The CA verifies you owned your domain and probably your identity as well, and sign your public key with their private key, this produces a certificate, which is a file that attests that the CA are satisfied that you fulfill their verification criteria. The certificate's authenticity can be verified by anyone with the CA's public key. Within the certificate contains, among others, your public key, your domain and identity information, and a link to the certificate revocation list (CRL).
When users visits your site, it receives your certificate. The user trusts your certificate because the user trusts the CA, the user checks that the certificate is signed by the CA and by checking the CRL the user also knows that the CA still stand behind their attestation of your certificate.
When you revoke your certificate, what happens is that your CA publishes a document in the CRL that tells users to stop trusting the certificate. What is revoked here is the CA's attestation of your certificate.
With Tor Hidden Service, there's no equivalence to a CA's attestation of your domain ownership. A Tor's key pair is akin to a self signed certificate. A Tor Hidden Service Key self-attests that it is who it says it is. Revoking a Tor Hidden Service Key is done by creating a signed document that tells other users not to trust the key used to sign the document. In essence, publishing a document that the hidden service is closed would suffice this requirement.