It's possible(?) that mozilla automatically generates a similar key for addon devs, but I definitely was not required to upload one when I first published this.

Honestly, I'm not sure what difference this makes. If someone really wants to hide their sale of an extension, they can absolutely include the usage of their dev account to the buyer, rather than making use of mozilla's system for transferring ownership.

If you're curious, here's the relevant section of code. I'm totally open to reworking it if you have alternative suggestions:

https://github.com/maxtheaxe/under-new-management-firefox/bl...

I'm hitting the AMO API directly, so you can see an example response of all the data I'm working with here:

https://addons.mozilla.org/api/v5/addons/addon/under-new-man...