I'm pretty sure they know.
I had the same issue. Fortunately, I had already created a Windows partition on my Mac, a couple of months earlier (btw, you can install Windows 10 without buying a key, you don't get the fully customisable version, but you can run games). I also had to uninstall some games to make space. But then, finally, I was able to try multiplayer.
Long story short : well, you can play with your friends. But get ready to spend a day or two setting up you computer for it.