In an unexpected twist, Sega announced that it is currently working on multiple games from several of its dormant franchises, including Jet Set Radio and Golden Axe.
They have to bring back Hideki Naganuma. He recently did some music for bomb rush Cyberfunk and based on his Twitter, he seems very much aware that Jet Set Radio is going to be his main legacy. I suspect he'd actually be pissed if they made a jsr game without him.