Not to sound mean but flash would be the last thing someone would consider trying to get on a modded console, mostly cause consoles don't support is as well as pc does, since adobe abandoned supporting it on anything not pc. Most popular sites now use HTML5 instead and flash still exist cause people have pre exiting sites that still have it. Most sites that have online emulators would probably use java instead which also is another thing consoles lack by default for a web browser.
Not saying you couldn't put flash on there, just is not a target for people of a hacking scene. Especially for a emulator, it be better to wait for a real emulator via homebrew or use another device in the mean time. Trust me, using online emulators isn't as good as homebrew ones, even on lower tier consoles.