I must admit that I do like the built in page translation, which I guess was made by a similar team using ML and all. Maybe I will like this too? Feels a bit... niche. Maybe it's a stepping stone to any misinformation at some point?
Edit This actually might not be coming as a browser feature at all. Mozilla is trying to increase the size of their Mozilla.ai team, so perhaps it's really looking for people with AI knowledge with web tech and a track record of using it for a ethical purpose. This team would be well placed to build pretty much any AI based tool for the firefox ecosystem.