It looks like Sonic Frontiers will have DLC, based on this promo

Sega selling add-on content isn't too surprising, but we may have our first soft confirmation of Sonic Frontiers DLC.

Sonic Superstars, Sonic Wiki Zone

Sonic News Nintendo Life

Sonic Frontiers Is Almost Half Price On Ahead Of Its Final Horizon DLC

Animated Short for Sonic Frontiers' Final DLC Released [U] - Games - Sonic Stadium

Sonic Frontiers Release Date Possibly Leaked By Promo Materials - PlayStation Universe

Sonic Central 2023: Celebrate Sonic's Birthday With New Releases and Updates - Xbox Wire

Sonic Frontiers might actually be Sonic Adventure 3

Sonic Frontiers might actually be Sonic Adventure 3

Sonic Frontiers' free story DLC The Final Horizon is available now: Tales, Amy and Knuckles are playable in the free update : r/XboxSeriesX

Sonic Frontiers Free DLC Update 1 is Here & News of the Next Sonic Game OwO

Monster Hunter DLC coming to Sonic Frontiers for free on November 14th - My Nintendo News

SEGA unveils post-launch roadmap for Sonic Frontiers

Nintendo Switch Sonic Frontiers + DLC + Name tag Korean Package PRE-ORDER

Sonic Frontiers' to receive free 'Monster Hunter' DLC

Sonic Frontiers November release date and DLC leaked by shop promo