It's probably cheaper for Google to ignore the complaints and foot the lawsuit bill when/if it ever comes due. They have the cash, and it seems like the attitude of companies like Google is to "ask forgiveness, not permission."
Federation was only addressed insofar as Moxie Marlinspike the developer noted it would be hard to keep the protocol updated if the servers were shared (he compared his tech to Facebook and WhatsApp, and described federated email as "stuck in time").
There's nothing unduly alarmist about the article, but it makes appropriate claims about (among other things) the security limitations that Signal has resigned itself to by remaining unfederated. Read TFA.
I don't know about the rest of you, but I'm here for the insights. Trying to court everyone just waters down the comments until HN is indistinguishable from reddit. I prefer apparent condescension and a thick skin over PC half-conversations and watered-down intelligence.