Here is a mockup of the upcoming DJI Osmo 360 camera by @hakasushi: Size comparisons of DJI Osmo 360 with DJI Osmo Action 5 Pro and Insta360 X4:
DJI has a recent filing with the FCC for a new DJI Osmo 360 camera and accessories (currently, only Rioch, Insta360, and GoPro have 360 cameras):