Unfortunately, that is only correct for the example cited in the article I linked to. The RFC being drafted contains attestation possibilities for both clients and servers, as per sections 4.1. (TLS Client as Attester) and 4.2. (TLS Server as Attester).

Nothing in this prevents servers from discrimincating against clients that fail to produce TPM-backed attestation that they run exclusively the exact software builds, cryptographically signed by a central arbiter of trust, that the server expects/requires them to.