Well, since it's nicer for community dynamics to have visible Favorites, I'd actually prefer that the default order of collections changes so that Favorites is displayed last rather than first.
Since Favorites was the only collection available until recently, I used it as a catch-all for anything memorable about any watch face. So in my Favorites, the quality is highly variable by my standards. That's why I would hide it.
Also only three collections show without expansion (for designers whose Favorites are empty). Since my Favorites aren't empty, only two of my own collections show without expansion.
User-specified ordering of collections and watch faces would allow users to top list different designs or collections on a custom rotation. It would also allow us to group designs with soft transitions between collections. Also, the most recent watch face is sometimes still a work in progress that will change with feedback. I'm still dissatisfied with my most recent watch face (I veer towards deleting it some days!) and yet it's listed first (cringe).