Well, it did drop to 3.9 stars. Initially, Google Play reviews got filled with 1 star reviews from users complaining that a lot of their workflows were broken,

Well, it did drop to 3.9 stars. Initially, Google Play reviews got filled with 1 star reviews from users complaining that a lot of their workflows were broken, things that they liked were removed, extensions not working (unless you used the initial nine excluded extensions). The rating dropped from 4.7 to 3.9 in less than a month. After that, some one star reviews were removed (maybe google thought it was review bombing or Mozilla used some kind of third party service for that). Ratings started to go up a bit after that. And suddenly a lot of 5 stars reviews with little to no content (thumbs up emojis, Nice/Great/Good, or just dots) started to appear and the rating almost returned to the previous normal. Nowadays is just a mix of good and bad reviews, most of them quite lengthy.