Sega will delist digital versions of classic Sonic games on May 20th

engadget.com:

Ahead of the June 23rd release of Sonic Origins, Sega announced today it would delist the standalone digital versions of Sonic the Hedgehog, Sonic 2, Sonic 3 & Knuckles and Sonic CD. Outside of a handful of Nintendo-related exceptions (for instance, Sonic the Hedgehog 2 will continue to be available through the recently announced Switch Online Expansion Pack), you won’t have the option to buy those titles through marketplaces like Steam as of May 20th. If you don't already own those titles after that date, you'll need to obtain them by buying Sonic Origins, which will remaster and bundle them together.    

The announcement comes just days after Sega shared the first details on the different versions of Sonic Orgins it plans to sell. In a chart that has since been roasted endlessly, the company revealed some of the collection’s new features would be locked behind DLC and special editions of the game. If you want the full experience, you must pre-order the “Digital Deluxe” version of Sonic Origins. Contrast that to the original releases of the games included in the collection: those shipped as complete games without the need for you to pay extra for additional features.