I've verified that 4.7.30 ( https://openshift-release.apps.ci.l2s4.p1.openshiftapps.com/releasestream/4-stable/release/4.7.30 ) was built with an updated coreos-assembler with https://github.com/coreos/coreos-assembler/pull/2406 and that `podman cp` works, whereas it fails with 4.7.29. So it should be sufficient to upgrade to that version.
*** Bug 2002120 has been marked as a duplicate of this bug. ***
The associated PR to coreos-assembler landed on Sept 2, so any RHCOS 4.7 builds after that time should have the fix. As noted in comment #3, the problem was fixed in OCP 4.7.30 and all future 4.7.z releases. We dropped the ball on the paperwork for this BZ, so we can't attach this BZ to the 4.7.30 errata that already shipped. Marking as CLOSED CURRENTRELEASE.
The needinfo request[s] on this closed bug have been removed as they have been unresolved for 500 days