As is clear from the name and graphics, My Island is a successor to Knizia's 2020 game My City, which was nominated for Spiel des Jahres. My City is a legacy game in which 2-4 players each use polyomino tiles to build a city on their own player board. The game has a 24-chapter campaign that introduces new rules and components, and you mark your player board with stickers and other items to permanently change your conditions for each subsequent game. My City also allows you to play a "regular" city-building game on the reverse side of each player board, with everyone competing the same way each time you change.
For more on My City, you can check out my written and video overview here.
If you look closely at the box of My Island, you'll notice that the tiles are formed from connected hexagons instead of connected squares. Aside from that, the only information KOSMOS has revealed are the basic deets (2-4 players, ages 10+, 30 minutes per game) and how this game mirrors the format of the earlier one: "Over 24 games, you will experience the history of your island and discover its secrets, with each of the individual games featuring new rules and game materials with which you will permanently change your island."
The other title KOSMOS has revealed is CATAN: Aufbruch der Menschheit, which was announced on the Catan Facebook page as CATAN: Dawn of Humankind. Aside from the teaser video on each site, the only info is this short description — "Explore the vastness of the world and the development of mankind as brave explorers hundreds of thousands of years ago" — so it's not clear whether this might be a new version of Klaus Teuber's The Settlers of the Stone Age or a new design set in the same time period.