Stuff like this, where flash is being replaced by html5+javascript, is what has me worried about Firefox removing the "disable javascript" checkbox from prefs (yes I know it can still be turned off in about:config but that's unacceptable). When we make javascript ubiquitous, these dark UI/UX patterns are only going to get worse.
Furthermore, why doesn't Firefox allow me more control over the data that's sent to and from my machine? The functionality that plugins like Disconnect and Adblock Edge have should be mandatory user preferences. There should never be a way for things like Flash LSO's and Evercookies to stay persistent in my web browser cache if I don't want them.
And we're still waiting on third-party cookies to be blocked in Firefox by default. That's been pushed back so much that I wonder if they faced too much outrage from advertising companies to make this happen.