Firefox 69: Flash disabled by default by Martin Brinkmann:

Mozilla plans to disable Adobe Flash in Firefox 69 by default according to an updated bug listing on the organization’s bug-tracking website.
Adobe Flash Player is the last NPAPI plugin that Mozilla Firefox supports; support for other NPAPI plugins like Microsoft Silverlight or Java was removed in Firefox 52. Firefox users could switch to Firefox ESR to continue using NPAPI plugins at the time. Google dropped support for NPAPI plugins in 2015 in Chrome.

Hang on. Mozilla killed of Live Bookmarks, RSS, the legacy extension ecosystem, and other bits but kept Flash around until … tomorrow-ish?