I think the rule of thumb is "If its too good to be true, it is"
TLDR:
No, its fake, and while you could reformat them, chances are it'll fail if you do.
I recall some Mac models in the past used to use non standard m.2 drives, which didn't get anywhere near that big, and the largest M.2 drive you can get at the moment is around 4TB. There are u.2 or other server centric flash storage of that size for eyewateringly high prices for servers, and Apple dosen't really make 'servers'.
No current mac model seems to do sata, which can get you up to 18tb a disk at 3.5 inches.
That said, various dubious chinese vendors are happy to sell you flash storage that lies about its capacity. I bought a 4tb one to take apart (and nothing else!). They're often a pair of USB keys or SD cards with firmware that claim larger capacities than they do, and they fail when you actually try to test them. Sometimes they even have a little extra weight.

I'd guess the "Mac only" label lets them stick on a price premium - or gives excuses should it not work. I've also had sellers sell me a 'fake' 1tb sd card, then claim they shipped exactly what was advertised. It was cheap and I bought it to test if it was fake so... I wouldn't buy it trusting that I'd get a refund either.