There was another article in NRC about Freenom and .ml. The main subject was that Freenom received a large number of sensitive defense related emails because people sent the emails to a .ml address instead of a .mil address.
In the article, they also wrote that the contract for the .ml extension expired last Monday, and the plan was to transfer control back to the Malinese government, but there was “some delay”.
So it seems very likely that we’re not seeing a temporary issue, but actually the full transfer of the .ml extension away from Freenom. And consequently the deletion of all free domain names using the extension.