I would be very surprised if a proposal that's at least over a year old (first commit in the GitHub repo was May 14, 2017) was part of some master plan for Goog

I would be very surprised if a proposal that's at least over a year old (first commit in the GitHub repo was May 14, 2017) was part of some master plan for Google to test their dominance after Microsoft recently decided to kill Chakra. Ignoring timing, it's a pretty terrible way to test their monopoly position since it's obviously not going to help Google's business unless they plan to start manufacturing the "3" key on JavaScript developer keyboards. Why would Mozilla possibly spend the effort push back on this? TC39 comes up with things that are controversial (on GitHub issues at least) all the time.