Earlier quoted context omitted.
Firefox just broke the bulk of their extensions, and I'm sitting and praying the APIs needed for non-broken gestures get implemented... I'm not being treated as a pawn, but it's still pretty rough.
The extension API change has been widely available information for ages now, with a significant migration period. If an extension developer chooses to not update their extensions, that's their choice.
It is impossible to update a gesture extension into something that works properly. The APIs don't exist. The workaround is to inject scripts into the page to track gestures, which means gestures don't work until the DOM is parsed, and don't work on about:newtab or other about pages.
Multiprocess had a significant migration period. Webextensions had "Well here's some APIs, we'll try to get you more before the day we switch. Some of the important ones are coming the version after, oops. And some are still missing but suck it up."