Yeah, I don't know. As I mentioned Open Source reporting is still kinda all over the place, and the folks that know for sure don't seem to be making statements.
I did see a couple folks hypothesize that since conventional warheads don't really exist for those reentry vehicles they may have just put in the testing weights that simulate warheads and let them be kinetic weapons. It would definitely send the same message, and explain the lack of secondaries. I don't know off the top of my head the velocities of reentry vehicles and if that makes since with the observed results.
I'm seeing the story has been picked up by legacy media, but people are still arguing over what it was. Kiev says ICBM and "Western officials" say IRBM. Either way our launch notification system would have tracked it. I suspect we know exactly what was used, and what it's capabilities are. Waiting on Ol' John Kirby to give us the official spin.