From an investor's perspective, updates from founders are helpful to stay on the same page and for them to be able to help you when you need it.
Daniel Gross, successfully sold Cue to Apple and is now an investor as part of Pioneer.
A great investor update might look like this:
<aside> ⭐ TL;DR: Include an honest executive summary with high points and asks/help needed, and how you're feeling about the business.
</aside>
Updates, experiments, and roadmap
Any exciting customers signed up? Any help needed?
What are you focused on, and how are you measuring it? You might be too early for that 😊