When Apple announced the Studio Display, they also announced that users had the option of upgrading the stand to one that allows for height and tilt adjustments, but users had to pay an extra $400 for it. It is an important choice because according to Apple’s website, the company stated that the stands are not interchangeable.
This means that if you choose to buy the base model but decide you want the height adjustable stand later, you can’t buy it separately and swap it out yourself. However, it seems that there might be a workaround. According to internal documentation obtained by MacRumors, it appears that the stand can be upgraded, but only at an Apple Store.
Based on the documentation, it suggests that if users bought the base tilt-only model but decide later they want the stand with height adjustment or the VESA mount adapter, they will be able to upgrade it by booking an appointment at an Apple Store or Apple Authorized Service Provider who will change it out for them.
This means that Apple will not sell the stand to customers directly, but users who change their mind later will have some form of recourse, albeit a slightly more troublesome one. We’re not sure if users will be able to eventually swap it around once they get their new stand, but seeing how seamless the design of the Studio Display is, it might not be a very easy process.