Microsoft’s 365 roadmap was updated containing a new feature called chat with self. Feature ID 88066 mentions that its release is scheduled for June 2022. The feature enabled users to create a Microsoft Teams chat with yourself.
Conclusion, opinion and summary
For some people this might seem to be an odd feature but it isn’t. On the contrary, it can be very handy. I can imagine some use cases for this feature. E.g. you are on the road, travelling or walking from A to Z in a large campus of an organization, something comes into your mind and you want to send yourself a reminder, so you send a chat message to yourself which you can later see on your other devices where you are signed in with your Teams account. In my opinion this is probably much faster as creating a new reminder in your calendar. Not slower than creating a new task in Todo. In case you use it like that you might want to add your chat with self as a favorite chat so that you can easily and quickly access your chat messages.