No. For simple economic reasons, such as too much testing effort vs. too little revenue.

For "simple economic reasons" you believe companies will go out of their way to block Linux users for some reason? If the browser supports it, that's all that really matters.

To support EME on linux, they need to create an EME plugin for linux. Leaks in that plugin would kinda break DRM, so it needs to be designed well.

Writing and maintaing a crypto plugin is quite expensive.

That plugin is called widevine and it's been shipped with chrome for Linux for a year or more. It's already done. They don't need to do anything.

wouldn't it be Google or Adobe who would write the plugin?

its not like they lack the developers or the such

Companies browser-sniff, rather than feature-sniff.

They shouldn't. But they usually do.

But don't get me wrong, I'd love to see your optimism come true here.

This does not add to the conversation. But it makes me giggle. And I'm not really a Linux user...

I'm assuming you are? And trying to foment a revolution? If I'm wrong see the first sentence.