I was already keeping up a devlog on the forum when the devlog feature launched, so I had to post my updates to both to keep them consistent which was a hassle, so not having to duplicate things would be nice. It was a very major driver of traffic for me back then. I feel that https://itch.io/devlogs is very crowded, it is very hard for me as player to see things I'm interested in playing, so having an option to filter there might make discovery easier. More metadata might also be nice there, since each entry tells me about the contents of the devlog posts, but almost nothing about the game itself. I really like the pop-up that appears when you hover over a thumbnail on other parts of the site, and having that here would help me a lot to understand the context of the devlog update on the devlogs page of a game I don't know.
On the forum, I like that all recent update are all visible on a single page, it allows me to just scroll past things and just looking at all the images until I see something that interests me. On game pages, posts are only discerned by a title and how long ago they were posted, more metadata there might be nice, maybe even a "Show All Posts" option? A view of devlog posts on the main game page similar to https://itch.io/devlogs with displayed images and excerpt for each post might help devlog posts be a more visible and prominent part of the game page.
I also feel that posting a smaller update (like just a screenshot) on the forum is more acceptable than posting a small news item with the devlog feature, because it feels more like a "News" feature in which you always post significant amounts of text about game updates or something. On the forum you can have a more relaxed conversation around the game, and I don't feel bad about posting "Didn't work on the game much, but here's one cool GIF of something I did work on!" there, where as with the devlog feature everyone gets notifications putting more pressure on me to actually write something meaningful. But maybe that's just me.