Who the fuck is Rivka Brown and what evidence do you have that JKR launched a suit against her?
Where is the evidence that JKR sued Nicola Spurling?
Spurling made a false and clearly defamatory accusation against JKR, and withdrew it on legal advice. I don’t see any evidence of a lawsuit.
Wachowski is entitled to his opinions about JKR as are Spurling and Brown, and they are all entitled to express them. Expressing an opinion is different to making defamatory statements, like Spurling and Brown did.
I have not the slightest doubt that if Wachowski said what Spurling said then JKR would have reacted the same way.