The good morning use case is awesome. We have some teams that have a room called "Good Morning". You can join there if you're the first one to start the day, and other can join you as they get connected.
I see few use cases here: one part is about a code you're working now. Like "what the heck is this?". or getting feedback on show some progress on the work you're doing, to show colleagues when you've finished a screen, mockup, or even slide for a deck, etc. I believe it's important for a remote team to have such moments, it gives extra motivation for both sharer and viewer, an improves feeling of a team work.
Also please consider making a mobile app for recording messages. Laptop is often used for a some heavy work, may be connected to an external display w/o any camera, so it becomes inconvenient to record messages from it. But an cell phone can do the job.
PS I will be glad to give more feedback. As you noticed, after having almost 20 years of work in remote teams I've put a lot of thoughts in a product like this, so will happy to give some help, you can reach me by igor@artamonov.ru