I have had this same issue on my M1 MacBook Pro since I received it in January 2021. It has happened with Disney+, Prime Video, Zoom (recordings), and Themis videos while using Safari, so far. I do not use other video streaming services on my laptop, so I cannot say if it would affect those too. I also do not use other browsers with these sites.
I have only noticed it with sites that use video, and the page will only reload while a video is playing. I wish the page did not automatically reload because on most of these sites do not save where I was in the video. It is also extremely inconsistent: I can return to the same video and never have the warning pop-up. It also happens consistently when I have only one tab open. I have no idea what conditions lead to the laptop registering significant energy use, and thus cannot avoid it.
I will say that I have had more issues with Disney+ that have nothing to do with apple products, so it seems their UX/UI is poorly designed in general. I often have to re-start videos, and sometimes the entire app, while using my PS4 because the video will freeze while the audio continues to play. Most of the time I have to re-start something at least twice before I can watch it all the way through. This also happens on my iPad Pro, though the issue resembles the one on my PS4, so I think it is a Disney+ issue. It is getting to the point that I am reconsidering my subscription; it is pricey for a product that is barely usable.