They have a lot of licensing deals going tbh.
- Bayonetta series with Nintendo
- Monster Boy with Game Atelier
- Panzer Dragoon remakes with Forever Entertainment
- Rez Infinite with Enhance Games
- Shenmue III (and IV?) with Ys Net
- Space Channel 5 VR with G-Rounding
- Streets of Rage 4 with Lizardcube
- The House of the Dead remakes with Forever Entertainment
- Wonder Boy Returns with CFK Digital
- Wonder Boy: The Dragon's Trap with Lizardcube
It seems this largely kept to IP Sega isn't taking an active consumer interest in though. I'd expect active CS IP like Sonic, Yakuza, Puyo Puyo, Sakura Wars, Phantasy Star, Shining, etc, to be off limits. Maybe they'd be open to 3rd party localizations though (like for Virtual-On maybe?).
TJ&E is owned fully by the devs btw. So is Ecco now. Sega only holds (shared) rights over the games they produced but not over the IPs themselves.