It's nice to see the combined interface in Teams notifications, and I'm willing to try it out. One thing to keep in mind with regards to group chats vs. channels is that a grop chat is often the fastest way to start collaborating and in my scenarios, there isn't the need or desire to set up a Teams site or look for an existing site to host the conversation. That being said, in most of my scenarios I would like to "promote" a group chat into a Teams channel conversation once an initiative gains some critical mass that permits it to use a full-fledged Teams site with all of the SP storage & functionality.