Accessing Files in Files Tab

It doesn't matter if you share the whole history, it's depending on how the file is being shared. When you share a file in a group chat (or channel conversation) you're really using sharing links and I can only assume that when you're adding a file you have a preset option of "people currently in this chat" or "specific people". If changing the sharing link to "everyone in my org" for example you know all belonging to the org. can access the file. As for now the person that has uploaded the file need to go to their OneDrive storage and "Manage access" for that file for others to be able to access it.

https://support.microsoft.com/en-us/office/file-storage-in-teams-df5cc0a5-d1bb-414c-8870-46c6eb76686a