I wouldn't believe them. The donkeys in retentions don't know anything about the traffic shaping in all likelihood, and I'll bet they're just saying anything to keep you as a customer.
I can well imagine them sitting there and saying "there's still traffic shaping, yeah, but it won't be as bad as before". It's unquantifiable, and since the topic of traffic shaping is so murky you'd never be able to tell if it was true or not. In other words, they can say what they want (within reason) and there's no particular requirement for it to be true.