[djf]

I may be wrong, as I often am.

But it talks about “water”.
Not “steam”.

[null and void]

I think just this one precious time, we can both be wrong.

Me because I missed this part:

“Most evidence suggests that subducting rocks initially hold water within their minerals, but that water is released as the rocks heat up.”

You because you forgot that under pressure the boiling point of water rises...