That’s how they do it. They send their “proposal” and immediately implement it in Chrome (with work on that being started long before “proposal” is made public obviously). Then they start using it on their own websites (with compatibility for now) and start propaganda campaign to push webdevs to use it too (which they do of course). Then they start complaining that other browsers’ developers are slow to implement this new “standard” (at this stage they won’t call it a “proposal” anymore) and are “stifling development of the web” or being actively malicious because they are jealous of Chrome or something. Then compatibility mode on their websites is first subtly broken so that users once again will witness how Chrome is superior browser and then removed outright. Boom, we have a new web standard!