I had to get used to it. Now I actually much prefer the name 'Disney Hollywood Studio's'.
I wish Disney would leave out the 'Disney' part of the name. It looks corny. If I were to say the name in full, it would sound ridiculous: 'Rest? Again? No, honey, let's hit the Disney Hollywood Studio's today!'.
That doesn't work. So in actual conversation I use 'the studio's'.