Sort of, but not really. They have a design document for how ZKP-based age verification would be implemented in the white-label prototype app, but it is my understanding that the first implementation to be rolled out in the early adopter countries like mine (Denmark) will be based on "trust me, bro" central verifiers who promise not to do logging, with ZKP mentioned as a possible future alternative. Until I see the requirement of ZKP or equivalent provable zero-trust privacy guarantees in the law, I consider the promise of ZKP as a distraction (lie) to shut down the harshest criticism.

Google Play Integrity is not a requirement, but governments think it is. All you need to avoid trivial duplication of certificates is that keys are bound to a device which is also able to perform the primitive cryptographic operations needed to construct a ZKP proof. This could be achieved using a USB dongle. Still proprietary technology, but the scope of what needs to be locked down is much, much smaller than with a solution like Play Integrity.