That definition specifies "artificial" limits, which would - I'd think - exclude technological limitations like oversubscription/saturation.
I doubt rules about advertising are going to change the market, the problem is that tens of millions of people are happy to pay for connectivity without really sweating the details of it.
Essentially, in any given month, you could get throttled/yelled at for going over an arbitrary data cap, which could (and did) vary every month. Given, it was usually above 1 TB, but it was still there.
ISPs got a book thrown at them by the FCC equivalent, saying that if they advertise their product as unlimited, it must be truly unlimited. Literally the next day that decision came out, all ISPs changed their adverts from unlimited to "at will" data caps, which essentially conveys the same marketing message, but isn't a regulated term.
Welcome to the new world, same as the old world, except where we've replaced a word.