Supposedly some kind of bump happens when a "major update" devlog is posted, with manual admin approval, but the lack of transparency and clarity around this makes it difficult to trust or plan for. I don't know what will actually happen to my current project when I release it, or whether the amount of time it spends stuck in the approval queue will impact its visibility. Even the quality guidelines FAQ flatly states that a project can never be put back at the top of the most recent list after publication, so what exactly does a major update do?
Incidentally, projects with no downloads don't appear in the search results at all - so an in-development project doesn't even get that initial boost to begin with.
I don't know what kind of possible exploit scenarios the admins have gamed out before setting it up this way, but it's not great from a creator perspective. It makes no sense that setting up a project presence ahead of time can potentially reduce your visibility when it's finished.