Great news! We just started working on this for the AUDIO portion. We are still trying to determine feasibility for the video portion of your request.
Suggest consolidating this request with https://microsoftteams.uservoice.com/forums/555103-public/suggestions/18844162-enable-voice-messaging to get more votes!
This feature is partially implemented at this point. We are still working on the last part of being able to play the messages thru the earpiece of the phone. Enjoy!
Furthermore, this is an EXISTING feature within Skype, which I understand from the Teams roadmap that Skype for Business is/has been transitioned to the video call features within Teams. Given Microsoft's path toward consolidating Skype for Business functionality to Teams, I see this is as a simple matter of bringing over another Skype feature into Teams.
My user base has people who really thrive off of having the ability to leave quick voice clip messages for each other. They're heavy users of Voxer, and rely on the ability to relate to each other's messages through the inflections and audible impression inherent in voice clips. This goes a LONG way with my user base, since it's an education organization.
This concept does merit consideration. Some Teams/Office 365 users need a way to have messages forwarded by SMS, in the same way they have auto-forwarding from their work/school email auto forwarded to their personable email. It can also act as a gateway process to get them to adopt the Teams app for their smartphone.
Thanks to everyone who volunteered for testing the Office 365 group calendar. The TAP team will be reaching out as we are closer to being ready.
We acknowledge the customer demand for Private Channels and have been hard at work on it. Private Channels is currently in preview with a select group of customers. We expect to release the feature to the public later this Fall, and will update here when we are starting to roll out to all customers. We appreciate all the feedback you have provided to us on this forum and thank you for your patience.