Most of the databases I (https://github.com/kubernetes/kubernetes/tree/master/test/e2e/testing-manifests/petset) and others (#28718 (comment)) have prototyped seem to handle DNS properly, but there are murmurs that some do not (#23828 (comment)), and dont' have plans to do so (#28718 (comment)).

I'd still vote for defering any implementation till we have the end to end models fleshed out. One might imagine that databases understand the importance of DNS ttl.