Get your taxes done using TurboTax

This is perhaps a new wrinkle, or at least new to me. If I buy the download version of TurboTax directly from Intuit (https://turbotax.intuit.com/personal-taxes/cd-download/), it asks me to choose between PC and Mac. So if I choose PC, will I still be able to install the Mac version, later? (Obviously, it's implying no, but in the past I always got both versions when I bought it from Amazon or Costco, so is it really limited when buying directly from Intuit?)