you seem to assume that the bandwidth used by netflix is fixed. however, what actually happens on network saturation (given net neutrality) is that both netflix and non-netflix content will slow down. netflix watchers will see buffering or will get a lower resolution.

that is the point of net neutrality: handling packets on a non-discriminatory best-effort basis. if the "channel is stuffed", then a certain percentage of all the packets in the channel, including the netflix ones, will be dropped.