Firefox 69 will force users to manually install Adobe Flash as the plugin inches toward end of life. Mozilla is disabling default support for Adobe s Flash Player plugin in the latest upcoming version of its FireFox browser. Adobe announced in July 2017 that it plans to push Flash into an end-of-life state, meaning that it will no longer update or distribute Flash Player at the end of 2020. Mozilla and Google have said that they would be disabling Flash in their browsers by default in mid-2018.
Source: https://threatpost.com/flash-default-mozilla-firefox-69/140814/