Adobe really wants to remind you not to use Flash anymore. If you haven't uninstalled the plugin yet, the company will send a prompt reminding you to uninstall it "later this year." And in 2021, it will block Flash content from running on its player completely.
Flash has been known to be riddled with security issues, and leaving it unchecked means attackers can exploit vulnerabilities. And now, Adobe wants to remind you that it's time to let it go in the past.
Source: Engadget