Echoing what other commenters have said, I can't square the supposedly surprised scientists with what I thought I already knew about volcanoes. Can anybody fi

Echoing what other commenters have said, I can't square the supposedly surprised scientists with what I thought I already knew about volcanoes. Can anybody figure out where the miscommunication occurred? Matching my layman understanding, Wikipedia says that an extinct volcano is one that no longer has a magma supply, but that dormant ones may unexpectedly become active. The article on the other hand speaks of dormant volcanoes supposedly being understood to have "empty" magma chambers, which structurally makes no sense, and should very clearly differentiate them from active volcanoes. Wikipedia says that the demarcation between dormant and active is so wishy washy that the term dormant is basically obsolete in the scientific literature. So what gives?