Sega has revealed that it will be delisting a bunch of Sonic the Hedgehog titles in the near future. The games in question are the ones featured in the upcoming Sonic Origins title, and are Sonic the Hedgehog 1, Sonic the Hedgehog 2, Sonic the Hedgehog 3 & Knuckles, and Sonic CD.
As for how the games will be delisted, it will simply be the digital stand-alone versions of them, meaning Sonic 1 and 2 will still be playable on the Nintendo Switch via the Sega AGES, and likewise Sonic 2 will remain part of the Sega Genesis application available to Nintendo Switch Online + Expansion Pack subscribers.
If you're interested in getting a digital standalone version of each of these games, be sure to do so before May 20, as that will be when the delisting takes place.