Allow customization of the root site collection. It has been made clear for a long time that for some reason the root site collection is unique and should remain uncustomized. The problem is that this just doesn't make any sense for business. They expect to be able to browse to the root of their SPO URL and see their custom portal. But we can't change the template or do much of anything with the site without breaking it. Whatever plumbing the tenant needs should be relocated out of the root site collection so it can be fully utilized for a branded intranet.