[jroseattle]

This is generally good advice with depth, but I would add a disclaimer: organizational practices and idioms should be taken into account. A few examples where these points would need some adjustment in my org:

We're not crazy about irregular cadences for project update communications. Why? Because there are many projects of complex size and shape going on. The stakeholders of my project care about many of those other projects as well, and they plan their schedules expecting to consume your update at that time.

Another case how we operate: the unpleasant surprise. Don't sugarcoat it, and bring things to attention as soon as possible. Rip the bandaid off, as we say.

As for tone and content, we focus on the purpose and delivery on that purpose. This is established early in the project, and our stakeholders understand both before the project ever takes off. We anchor our updates on those aspects, as it gives stakeholders an understanding of progress, no matter what the project update includes.