This feature request has now moved to “working on it”. The team is actively working on this request and I will share more details as they become available.
I just saw that this was backlogged and I am sad to see that. The #3 issue that is listed in the main post here is our biggest issue in moving forward with Teams as a company. Anything we try to share in channels is then extremely difficult to search for later (well we can find it, but as # 3 suggests it takes manual scrolling, and in some cases through months of chats). This has been our #1 frustration and is also causing us to find alternative options for team sharing and communication.