The author is clearly delusional and narcissitically unwell. This has no place here.
Those sorts of attacks work on an author who has only been ripped off by one publisher, but when there are six or seven, the attacker ends up looking like the nut job. Just wait until next year. Somebody delivered this as a poison pill to the whole industry. When the same new story shows up in seven locations within two years, bad actors are easier to identify.