In this video, an Alaska Volcano Observatory scientist discusses what happened to that plane.
And here is that 2010 video again, showing what can happen when jet engines and volcanic ash mix.
Of note, a few months after KLM 867’s close call, Redoubt did this:

Volcanoes look all cute and steamy and chimney-like, until suddenly — apocalypse! (Image: J. Warren/Alaska Volcano Observatory)
Fortunately, at the time of writing Mount Redoubt is asleep.
And volcanic ash advisory centers are now a thing.
Featured image: Bauhaus345, via Wikimedia, CC BY-SA 3.O.