Green explicitly mentions Kyber in his post.
> NIST-approved schemes based on lattice problems include Kyber and Dilithium (which I wrote about recently.)
> Chen’s algorithm does not immediately apply to the recently-standardized NIST algorithms such as Kyber or Dilithium.
And it's not just Signal. Apple's new iMessage protocol, PQ3, uses Kyber, too. [1] Most deployments of PQ-crypto that I know of have used Kyber.