Netflix has never stopped "throttling", perhaps it has gotten better over the years as they opened more distribution centers & expanded their library, but it's never gone away. They are rather vague about how it works & don't want to explain it to customers which is why they tuck it deep in their DVD Terms and Conditions.
DVD Terms and Conditions
As a result of your viewing habits and our operational practices, the actual number of DVDs you rent in any month may vary, and you may experience differentiated service during the course of your membership. Also, such service may be different from the service we provide to other members on the same membership plan. The type of differentiated service you may experience includes, (i) the shipment of your next available DVD occurring at least one business day following return of your previously viewed DVD, (ii) delivery taking longer, as the shipments may not be sent from your local distribution center and (iii) the DVDs you receive coming from lower in your Queue more often than our other members.