Mate, we’ve been making gravys and thick sauces before the Brits came along. Especially people in coastal regions who use coconut in nearly everything.
Careful, that’s like saying that the guy who made it, who was born in the UK isn’t really British either.
Umm what so you mean by ‘the guy who made it’? Curry has existed in Indian subcontinent, in various varieties, for hundreds of years. It wasn’t first concocted in UK in 1960s.