Account creation is a very high bar when it comes to Apple services, because Apple "console bans" hardware devices associated with accounts that evidence fraudulent behavior. I expect they will only seriously consider reports from users who have an active Apple hardware device bound to their Apple account.
I also expect they'll link this system to a human review queue. If you send abusive reports for something that isn't scammy, it will probably not be considered scammy during human review, especially if you're responsive to questions asked by Apple during that review. There will, of course, be a 'first post' false positive someday when a reviewer makes the wrong call, but it's a safe bet that they have not implemented a Google/Facebook/Yelp system where your life and livelihood can be destroyed by an algorithm without human participation.