Enforcing vague rules is always problematic. The rule itself is intrinsically problematic, because people will see that others get away with it, often for seemingly no reason. While the OPs case looks clear cut, rules like this are always going to catch out people small hard to explain changes will cross the invisible and likely fuzzy line at moments people don't predict correctly.
And that further underlines the need for a grace period, if this really is the best model cloudflare can come up with (presumably it is).
I'd imagine vague rules allow them to give their customers leeway and handle infractions on a case by case basis. Like a popular open source project could get away with a cheaper plan, while on AWS they couldn't.
I think this particular instance is pretty cut and dry. If I understand correctly, they were just reselling cloudflare's services.
However, I DO think under that vague policy they should issue warnings for cases they seem inappropriate
And that further underlines the need for a grace period, if this really is the best model cloudflare can come up with (presumably it is).