That's what's being proposed at the W3C.
The security risks cause me imagine EME news that makes the recent Java 0-day news frighteningly tame.
But worse than that, the working of the DRM (called a CDM) will also sacrifice your privacy on the web, because it can inevitably act like a "supercookie" over which you will have no control.
The EME (again, by my understanding, I could be wrong) only defines an API to communicate with DRM systems. I don't think this helps us gain any scrutiny over DRM.
The HTML DRM (EME) is nothing but a plugin API. The plugin is something like Widevines DRM, called a CDM, (already in use on chromebooks) that browsers will no install on your machine without your consent.
The working of the CDM/DRM itself is not specified in any way. Repeated request at specification have repeatedly been rebuffed and ridiculed by Google, Netflix and Microsoft.