macOS is UNIX, certified UNIX actually.
But I mean, if someone had the merest impression of macOS and was very familiar with Linux and never bothered to look any further then I'd understand. Maybe they only played around with macOS a little and saw the terminal app had bash and most all the familiar tools as on Linux. It's not hard to see why they might've thought it's Linux based.
People when talking about EU banning US social media and fostering domestically-based networks: hell yeah ๐๐๐
When China does it: evil commies! Brainwashed! Chinese people are too stupid to see they're being manipulated!