Huh? I'm very confused as to what you mean. It's a customized version of Android. All the Android multi-tasking and app pause and resume life-cycle stuff should still be in there. Most of their ecosystem is heavy duty games that use all the device's resources (kicking out other apps from the working set), but it's definitely a multi-tasking OS.
I really do not think 3D widgets would require an entirely new OS. The main app switcher would need a revamp and they would need to re-purpose or build out some new app life-cycle callbacks to handle widget focus and interaction but it all seems very doable and not much harder than what they've already done.
Too me it sounds like what's being described is just a 3d desktop. But, in the walled garden world we live in most people just call the os/desktop combo the "OS" when it comes to android/ios.
I really do not think 3D widgets would require an entirely new OS. The main app switcher would need a revamp and they would need to re-purpose or build out some new app life-cycle callbacks to handle widget focus and interaction but it all seems very doable and not much harder than what they've already done.