Granted planets get destroyed a lot in Vanguard but this would be kind of a big deal even if it was covered up. But the timing is right for a "reason Ceti Alpha VI" blew up explanation, provided the Mutara Sector is part of the Taurus Reach.
It isn't. After all, Ceti Alpha (which should actually be Alpha Ceti) is self-evidently in Cetus, not Taurus. It's in the Beta Quadrant, maybe a couple of hundred light-years from the vicinity of Vanguard.
Besides, the explosion of Ceti Alpha VI and the alteration of Ceti Alpha V's orbit were already explained in To Reign in Hell as the result of a cosmic string passing through the system.