After listening to your feedback, bug 1203584 was filed last week to turn off signing requirements in Firefox 41 and 42.  This extends the signing deadline to Firefox 43, which will be released around December 15, 2015.

While the new unlisted queues have maintained a quick turnaround time (thanks to the tireless efforts of Andreas Wagner, aka TheOne), many developers are telling us they simply don’t have enough time to implement the requested changes before the September 22 deadline when 42 hits the beta channel.  In addition to giving you some extra breathing room, we’re also going to use this time on our side to make some improvements to the submission experience to make it clearer what level of review is needed, which you can follow in bug 1186369.

Thanks for your patience as we roll out this new process.  Special thanks to those of you who have already gotten your extensions signed…you’re awesome.

https://blog.mozilla.org/addons/2015/09/16/extending-the-deadline-for-add-on-signing/