I do not quite understand what you are talking about.
Uploading on a new account will not help promotion.
Deleting and reuploading will not help actual promotion. If you all you get is 5 minute fame for being on https://itch.io/feed?filter=new_games that is not promotion. It is accidental traffic. Building an audience this way is playing lottery games. And regular users will recognise you and might report you for spamming.
If you upload a new project that actually is an old project you lose your audience. You start at 0. No comments. No ratings. No collections. No trust. You do not want to be found in https://itch.io/games/newest you want to be found in https://itch.io/games (that appears when you click "popular" and is the default sort)
You can get the 5 minute boost again if you do a major update and post a devlog about it. But those have to be approved by staff and they do not do that for all devlogs.
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If you complained about the misleading naming of the recent section, I agree!
They should make two recent sortings. One for updates, so the people doing updates without bragging with devlogs are sorted accordingly and a sorting by publishing date. With added protections against abuse and spamming. Because that's what people will do. Abuse the system for that 5 minute fame, because they think that being visible on recent is promotion.