No, it won't. As far as compatibility goes, EME is even worse than something like Silverlight. This should be evident just from the fact that in order to use HTML5 Netflix, you either need a) IE11 on Windows 8.1 or b) an official Google Chromebook with Google-provided image and which hasn't been rooted. In comparison, even Silverlight has a pretty amazing track record as far as compatibility goes.

EME, MSE, and Web Crypto are very new specifications. They’re just starting to be rolled out in browsers. They’re not going to be rolled out everywhere overnight.

H.264 video codec is on pretty much every major browser now, including Firefox. This wasn’t the case when browsers first supported the video element. It is a similar situation to EME and friends today. Including the potential licensing fee (I assume vendors have to licence the DRM module to plug into EME or get it from the underlying OS in the same way to how they have to licence H.264, but I'm not sure about this area)