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 Frontiers DLC 1 - 'Sights, Sounds & Speed' - Coming March 22 - Games - Sonic Stadium

Sonic Frontiers release date and DLC 'listed by promo material

Sonic Frontiers' First DLC Offers Free Monster Hunter Goodies

Sonic Frontiers' Free DLC Roadmap Includes New Playable Characters And Story Content

Ian Flynn Will Return To Write 'Sonic Frontiers' Third DLC — CultureSlate

Sonic Frontiers Free DLC Roadmap Reveals Tons of New Content Coming in 2023

Sonic Frontiers Gets New Promotional Artwork - Gameranx

Sonic Frontiers DLC be Like..

Sonic Frontiers Is Offering Free DLC Under One Condition