It absolutely is a problem with the article. Science deals with physical phenomena; metaphysics quite literally means beyond physics. It's ridiculous to say that consciousness is the last hold out, as if there aren't a million other unanswered questions about meaning, essenence, and experience.

Here is a parallel argument for you. The history of science has been one discovery after another which leaves us with new, increasingly complex unanswered questions about phenomena. It is reasonable to think that if/when we reduce consciousness through science we will find that there are more increasingly complex unanswered metaphysical gaps.

Reducing a complex phenomena to more basic structure and dynamics just is to eliminate any open metaphysical questions about that phenomena. That's why the big philosophical debates center around monism vs dualism rather than n-pluralism. Science has dispatched all other essences from mainstream consideration.