IMO, wild overestimate. People don’t watch movies that often.
How much bandwidth is one movie? How much time would you have to spend on sites like this to equal one movie? One YouTube video of a few minutes can equal all of a day of regular surfing.
The don’t have to watch often to add up to 1/3 of peak time flow. All it really means is during that time when the most people are on the internet a significant chunk of them are streaming a movie from Netflix. But it’s all relative measurements, could be 20 people of 300 streaming, or 200,000 out of 3,000,000, don’t know because that’s not the numbers being presented.
First, I don't know if its an estimate or a calculation using actual records.
Second, I will add anecdotally that just tonight my kids and I watched a 1080p movie streamed from VUDO (Like Netflix only per movie charge instead of monthly) and last watched one only a week and a half before.