I was not aware of the text that you mention, however i assure you that the iso files were there, for (at least) the past five years. I know because (in earlier distro researching (!) eras) i was downloading from the related locations at least once a month, or i was visiting that location for finding out the sha256sum files to re-check stored isos prior to re-using them. I have a downloaded 10.0.net-install version from November 2020, from the debian iso archive (no jigdo, just plain wget), along with the sha256sum file. So the change is very real and very recent, make no mistake.
Panos