I'm FB Friends with him, and he's still around on the internet. Not sure why he left here. His profile has him last active in June.
I have also noted an increase in sharp words around here. Perhaps it's lighter moderation, perhaps in symptomatic of the increasing divide in American Culture, perhaps politically minded folks are retreating farther into their corners and circling the metaphorical wagons. Perhaps it's some combination.
I would note that just the "normal" social media platforms have gotten more rancorous in the last 12-24 months, so it's not too surprising that that eventually leeches out into other corners of the internet.