Itch will not tell you why or why not a major devlog is approved to push your game on top of recent again. They do not like people trying to game the system.
Your account is 41 days old. Number of expected approved devlogs: 0. You seem to have gotten one. Lucky you. Some games wait to get indexed first time for a month.
You have over 250 followers in that short time. So you are doing pretty well. So you should not worry. Do your devlogs/updates for the sake of it and not to optimise any perceived bonus attention. A devlog itself is already a bit of promotion, because they appear in https://itch.io/devlogs