I've said this before and even made a thread about it, but I feel that Valve should create a mandatory patch note system that automatically releases the information as an announcement as it seems that every time a game is updated without a corresponding announcement/thread, you see people wondering what changed, and such a system would also make it clear whether the "update" Steam is downloading is a patch or a new data depot (no new announcement = game hasn't been patched). There'd be nothing preventing developers from just writing gibberish, but the difference in effort between mashing the keyboard and actually noting what the patch addresses would be minuscule, so I think virtually all devs would bother to write a helpful changelog (even something as mundane as "Fixed some sprite rendering bugs" would be better than nothing at all).
