Im not 100% sure if that is even possible in RL, but if it is, here is a suggestion:
You could implement a Mechanic, wich rips a Planet apart, if it spins to much and the crust reaches and exceeds escape velocity. Maybe it would also get heated up, before it fragments.
you basically just would have to make it the same with the roche fragmentation, just with the spin and gravity of the planet as trigger