The cessation is for the five aggregate after an Arahant dies
AN3.47
“Bhikkhus, there are these three characteristics that define the conditioned.405 What three? An arising is seen, a vanishing is seen, and its alteration while it persists is seen. These are the three characteristics that define the conditioned.
“Bhikkhus, there are these three characteristics that define the unconditioned. What three? No arising is seen, no vanishing is seen, and no alteration while it persists is seen. These are the three characteristics that define the unconditioned.”
It is not a cessation of everything that would be nihilistic. Nibbana does exist. Because it exists, that is why we have a way out from suffering