You purposely cut out that they are shipping shadow dom in conjunction with Mozilla. That was literally the next statement where you cut your quote. And if you continue to read the conversation this was all talked about and is basically a draft spec, they just haven't finished writing it up, but all the talking and consensus building was done and documented in the f2f minutes.
> that they are shipping shadow dom in conjunction with Mozilla
With my Mozilla developer hat on, that happens not to be the case. Which you would have known had you either read the entire linked-to thread, or even just read the mail that was linked to, which points that out explicitly in the "notwithstanding your apparently inaccurate statement about Mozilla" bit.
> That was literally the next statement where you cut your quote.
It was also a misrepresentation of what's actually going on. Quite common out of Google these days, unfortunately; we've had to call them on it publicly a number of times. Not that this is stopping them from continuing to claim that others are OK with something they're doing when that happens to not be true.
> but all the talking and consensus building was done
The only thing discussed at the CSS working group f2f was the cat and hat combinators, not the entire shadow DOM spec. And even for those, serious issues were raised later by people who were not present at the f2f.
For shadow DOM as a whole, there is no consensus at all. Mozilla is not really on board with the spec in its current form (and we've said so repeatedly and publicly, though we do at least have a plan for how to get the spec to something that we'll be OK shipping... which won't match what Google is shipping). Apple is very definitely not on board at all with the spec in its current form, and Google is not even trying to get them on board. Microsoft has basically said nothing apart from having concerns.
In addition to that, the spec doesn't match Google's implementation at all, in all sorts of ways that are obvious if you actually stop to read what the spec says.
Basically, Google implemented and shipped whatever they felt like and made a sort of attempt at specifying something or other which totally doesn't match what they shipped. And other UA vendors at best (Mozilla) plan to ship something somewhat different from what Google has shipped and at worst (Apple) think the whole thing needs to go back to the drawing board because it's just broken by design.
If you don't think that's unilaterally shipping before standardization, I'm not sure what you think it is, exactly.
