This sounds like an excellent idea. itch.io has so many different categories of stuff on the site, but no way to categorize our own stuff. Seems like a no-brainer, especially when you start building up a big catalog!
Along the same lines, I think it'd be neat if we were also allowed one Featured project at the top of a profile, under the banner. That way we could really focus a visitor's attention say on our newest project, a sale, or whatever we're most proud of, while keeping the same itch.io styling you see at the front. Like, say there was a little star icon next to each game in the Game Display order, and if you click a star to make it yellow, you get a big banner like on the homepage for that project, which shows the title, price, and platforms by default, and screenshots when you scroll over it.