It's very difficult to prove either way. There's also the factor of making a big deal of removing Denuvo post release; if sales were lost due to its inclusion, does it fully recoup those? Does it actually result in more total sales?

Whether it actually causes measurably more sales, my thoughts are that if paying customers are treated worse than pirates, then piracy is justified, so including Denuvo inherently justifies pirating the game to me.