Hi Bromelee,
Yes that could be a way to make a devlog. You could also report a problem during the making of the game and describe how you solved it. Or how you implemented the most important game mechanic. Or how you arrived at your final game idea. Or a day to day schedule of what you did each day. Many possibilities as long as it has something to do with how you approached the development of your game. Other participants can learn from that and vice versa.