Adobe announced <here> today that late 2020 will be the official end-of-life for Adobe Flash. Microsoft posted a tentative schedule for the gradual phase out of Flash from Microsoft Edge and Internet Explorer in their 25-Jul-2017 blog entry The End of an Era – Next Steps for Adobe Flash.
Kudos to Woody Leonhard for alerting his AskWoody.com readers in the post Adobe announces the end of Flash in December 2020.