Maybe they announced this a long time ago and I just missed it, but they really didn’t make it obvious. There was no email heads-up, and in the app, you have to click through into an affected device to learn that it’s even going to be an issue, which is not something I do at all often. Sure would have been nice to get a notification in the main app screen or something. More info here:
https://support.eero.com/hc/en-us/articles/4401964665243-eero-Software-Security-Updates