NPPs are some of the power sources with the longest service lives.
True, but they do have finite life spans, they do have end-of-life dates. They cannot be maintained and operated forever.
There may be some debate on how long they can go before they need to be decommissioned, but it is understood they all need to be decommissioned at some point, because they will fail catastrophically if they don't.
And they are one of the, if not the most important, structures that we should be more safe than sorry about, and decommissioned them earlier rather than at the last moment, for safety reasons.