I’m really not happy about this, I would have turned off auto updates or something if I would have known. It’s so insulting that the message redirects us to an URL but there’s no Safari app on AppleTV!
I do live workouts on Facebook video streams, and I specifically bought the AppleTV at Xmas for this. My AppleTV is hooked up to my modem via Ethernet so it’s a faster connection because I have people using wifi for remote working / schooling. I can screen mirror from my phone but of course that’s wifi.