Yeah, I have an installation of MediaElementJs manually added via HTML pages and it works in IE8 w/ Flash Fallback:
https://progressionstudios.com/player/demo/ (HTML Pages with MediaElementJs added manually)
However when I use WordPress and the shortcode (Or manual URL add), it doesn’t work in IE8 (Does Work in all other browsers IE7, IE9+, Chrome, FireFox, Safari).
https://player.progressionstudios.com/ (WordPress Example)