This is true. In fact, in order for Netflix's HTML5 experiment with Google to be working in the first place, they had to develop a preliminary version of the spec as a working test case to submit to the W3C so they could promote it as a standard (which is how browsers eventually obtain new features--W3C specifications from Working Drafts, mostly).
Originally Posted by ADGrant
This means it no workie in the Touchpad 3.0.x browser. It simply doesn't support anything proposed since late 2010 nor final specifications for substantial parts of HTML5 that's been changed since then. It's why it gets an abysmal HTML5Test.com score compared to those platforms that conduct updates--currently at a 224 score when the other major players (except for Android 4.0's old and obsolete default browser) start in the mid-300s into the 400s.
It also means, for Open webOS, that they'd need to rebase to the first version of Webkit that supports it after Webkit consumes the extensions from Blink (assuming it's in Google's fork rather than Webkit mainline, which is what it sounds like).
So, just because it says "HTML5" it doesn't mean anything for those that have been wishing for Netflix on their Touchpads; the support for the proposed DRM extension to HTML5 simply isn't there and would require a complete Webkit update, which means realistically you'll still have to install Android to get a Netflix experience at all.