They aren’t against the rules, we just don’t index placeholder pages or pages that are just links to somewhere else. We want people browsing the itch.io main site to be viewing games they can access on itch.io. That doesn’t mean you can’t, for example, use itch.io pages as a portfolio with your work that is hosted elsewhere. It just won’t be promoted by our discovery tools.
Just because a game is “deindexed” doesn’t mean it’s breaking the rules. It just means that we aren’t promoting it from the main site.