Well this is an interesting one. A lot to unpack and a lot of it might come down to definitions and assumptions of meaning. I found a lot of things I agreed with, like rethinking our 'special' place in nature, and the integration of all life. But since I have long since dispensed with the word humanism, for the reason that it can mean anything and everything, I can't see myself embracing posthumanism. I'm not convinced that negative connotations that the author associates with 'humanism' really stands up either, or why adding 'post' to humanism reinvents humanism for the 21st century. The author seems to have a sanguine view about the integration of technology and biology in the human body ( a Millennial view perhaps?) but for myself I rather worry we are on the road to become something like the Borg in Star Trek. Yuk! Interesting ideas in this piece, but I don't care much for the word humanism and i doubt 'posthumanism' will grab me either.
It seems to be the same old story of rejecting concepts or people out of ever more stringent litmus tests. Humanism is associated with x because y said so, so throw it all out. The bigger issue is that of practicality on the ground. The US might be seen as one of the most advanced countries, and yet we see intractable political problems - - intractable insofar as humanism is in no position to even work towards changing their causes. Really, Humanism is a dodge from the responsibility of fighting to stop the evildoers. Were the Resistance fighters Humanists?
Your reference to the Borg is well taken in my opinion. Young people no longer have an option except to plug into the corporation dictated crypto-fascism. We are already enslaved if we have no options to participate in the REAL decision-making.