Well, it probably takes a while to be reviewed. This isn’t something you should solely rely on; appearing on the “newest” games list is hardly called promoting. Not just that, by deleting your previous game, you destroy any links to it on the app, any purchases made by customers and comments by reviewers.
Well, maybe you should try it yourself? I get it, you try to be reasonable, but I don't see any updates for your projects and I assume that you don't know what are you talking about. Please correct me if I am wrong.
For me, as an indie game developer number of views means a lot. Like at this point after I updated the game my number of views remained the same. It is impossible to promote the project this way. So while I agree with you that it is better to have your project updated than making a new one with every new version, I just don't see another way for now.