Microsoft Edge Will Start Automatically Pausing Less Important Flash Content (venturebeat.com)
An anonymous reader cites an article on VentureBeat: Microsoft Edge will "intelligently auto-pause" Flash content that is "not central to the webpage." If you want to try this out now, you can take the feature for a spin with Windows 10 build 14316, which was recently made available to Windows Insiders. Peripheral content like animations or advertisements built with Flash will be displayed in a paused state unless the user explicitly clicks to play that content. This significantly reduces power consumption and improves performance while preserving the full fidelity of the page. Flash content that is central to the page, like video and games, will not be paused. Microsoft wrote in a blog post, "We encourage the web community to continue the transition away from Flash and towards open web standards. We are planning for and look forward to a future where Flash is no longer necessary as a default experience in Microsoft Edge."
Wait until Flash dies and people use JavaScript to animate HTML5 tags and such. How are you going to selectively block that?
Not that hard, at least in Chrome I use Disable HTML5 Autoplay plugin.