Yes, but Federer and Nadal are both 6' 1" tall and they have dominated ATP for last 10 years.
I do think there is definitely something to the taller theory though. I can remember in the wood racket and early graphite racket days with gut strings that shorter players could move tall guys around and make them hit lots of low balls. Tall guys could hit big serves even with wood/gut and early graphite/gut but they could not hit the thundering topspin groundstrokes that stay in the court that modern graphite/co-poly allows them to hit. Get rid of co-poly and restrict racket size and width and I think you would see the tall guys struggle a lot.