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 Limited release Shoes DLC XBOX (N.A. region)

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

NEW Switch Sense: A Cyberpunk Ghost Story (HK, ENGLISH/ Chinese). Switch Ninja Gaiden Master Collection 1 + 2 +3 (HK, ENGLISH/ Chinese/ Spanish). NEW

NEW PS5 Sonic Frontiers (HK, Chinese/ English/ Japanese) + DLC

Sonic Frontiers' First Free Content Update Is Out This Week And Here's What's In It

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

Sonic Frontiers (2022), Xbox Series X, S Game

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

Free Sonic Frontiers DLC Will Add New Characters, A Photo Mode, And More In 2023 - GameSpot

Sonic Frontiers Prologue is Now Live: Prepare for Sonic's New Adventure!

Tails' Channel's Ultimate Sonic Frontiers Guide and Summary: Everything you need to know - Tails' Channel