Hi Daniel,
Thanks for your interest in Studio One 4!
We’re offering a 60-day grace period for users that just bought Studio One 3. If you purchased Studio One 3 between March 22, 2018 and May 22, 2018, you’ll automatically be upgraded to the corresponding version of Studio One 4. This change may take up to 48 hours and will show up in your my.presonus.com account once available.
If you purchased Studio One 3 outside of this window, don't worry! We're not forcing you to upgrade nor are we discontinuing support for Studio One 3. You're still free to use your copy of Studio One 3. However, if you'd like to upgrade to the latest and greatest, you can find the appropriate upgrade path here: https://shop.presonus.com/products/software/Studio-One-4-prods/Upgrades-Crossgrades-S14