I'm suspicious of how Tether is operated and whether it's actually backed by any fiat. There's also been a lot of interesting Tether movements and emission before BTC price surges in the past. But I don't know the truth and might not learn it, ever.
But things like this are outrageous. This is just cheap. Although I don't understand the motivation of this guy to spread FUD about Tether in such a way. What could that be?