That seems likely. Computex reveal with Summer release
I'd love that, but I think they will still stagger it. The larger caches per CCD is a big marketing point, so even the non-X3D chips should be better at gaming. The single CCD nature of the new 12-cores also makes AMD's 12-core CPUs a lot more viable for gaming. Until now, their Dual-CCD nature has been a problem.
30% IPC gains sounds nuts. Too good to be true kinda nuts. That said, IPC changes are crazy workload dependent. Some workloads could certainly see those kinds of gains.
Zen 5's Math Acceleration Unit comes to mind. 32% gains in single-core Machine Learning and 35% gains in single-core AEX-XTS was marketed. Big gains, but not representative of all workloads. Will need to look into the newest rumours.