Sega really should do more wit htheir Classic-era IPs. We need Shinobi.
They already did it 2 years ago in SEGA Ages,
and I kind of love it back then.
But the sale wasn't that good,
it was still far below SEGA Ages: Puyo Puyo, Outrun, and Virtua Racing.
I heard Dotemu (Streets of Rage 4) has pitched Shinobi sequel,
but SEGA hasn't agree yet.
They even failed to put Joe in Streets of Rage 4.
Although they pursued use of Joe Musashi from Shinobi,
the licensing, different departments, and various permissions necessary to use a character like Joe Musashi made including him as a bonus playable character impossible.
Full article :
https://www.shacknews.com/article/118056/streets-of-rage-4-almost-had-a-guest-character-from-segas-shinobi-series