Yeah, you're right to not trust that statement.
1.7 million might seem realistic to someone from the good old "lol dead gaem"-crowd, but that crowd was always grossly underestimating the game, even when subs were revealed.
If they say 1.7, I'd instantly think triple that amount. But since I'm not taking their word for it, any number is needless. MAUs increasing/decreasing and the odd mention of increased sub count = all we get these days.