I got that popup after it put a background page into low-mem state. It told me that it had done it and that I can disable it. I think it gave me a link to the s

I got that popup after it put a background page into low-mem state. It told me that it had done it and that I can disable it. I think it gave me a link to the settings location. Most of the people who don't care about browsers will be accustomed to having their state erased anyway when something like a page-reload or a navigation-action has been made, so I think it's fair to enable it by default. The benefit they get by it outweighs the side-effects, specially if you consider your first point.