Yes, any metric can be gamed. But I believe measuring the entropy of a repository, comparing state of the code-base over time can be done deterministically, which would make it harder to game it.
So either we are going to completely avoid automation and create a community council to decide what deserves to be shown to rest of the community or just let best AI models to decide if a project is worth show up on front page?
Or we can do all of the above :)