They announced a while ago that they were getting out of the "distributed books as files" (aka buying ebooks and getting the files on members.oreilly.com) game, and doubling down on the "subscription service to consume books online" game (aka Safari). This is just another step in that process. See
https://www.thebookseller.com/futurebook/why-oreilly-media-n... for the original announcement.
