The last paragraph discusses how he's resisted the label and then he closes with “the rationalists have walked the walk and rationaled the rational, and thus they’ve given me no choice but to stand up and be counted as one of them.”
Oh, you're right! I'd add that it's actually the penultimate paragraph of the first of two postscripts appended to the post. I should have read those, and I appreciate the correction.
He’s clearly identifying as a rationalist there