This extension is listed under about:debugging.. the same place where you'll see other features like Pocket, Form Autofill, and Firefox Screenshots.
It's a new Firefox feature. It's not alarming, and it's not Firefox installing things without your permission.
Complaining about this is literally complaining that the new version you just installed has a new feature. If a new version didn't change anything, they wouldn't need a new version.
https://blog.mozilla.org/futurereleases/2018/06/25/testing-f...
This extension is listed under about:debugging.. the same place where you'll see other features like Pocket, Form Autofill, and Firefox Screenshots.
It's a new Firefox feature. It's not alarming, and it's not Firefox installing things without your permission.
Complaining about this is literally complaining that the new version you just installed has a new feature. If a new version didn't change anything, they wouldn't need a new version.