Not in the last 1000 years, no, but - they do mention they think there have been 11 Lahar events originating from Ranier that have impacted the seattle area, over the past 6000 years - one of which doesn’t even seem to be associated with a volcanic eruption.

At first I was like “why worry about Ranier when Hood is active” but - yeah the mother of all flash-floods is a horrifying prospect.