Will I be able to opt out from this?
I'd assume that you can use a browser that doesn't send this data?
Until Google sites start deliberately breaking if you don't send this data (or your browser is known to implement any other feature intended to circumvent it), thereby destroying the market share of any browser that dares to do so.
You can send bogus data in this case.
I mention this. If Firefox were to come out and say "we're going to start spoofing this data", Google servers would start rejecting Firefox users within the week. No major browser would dare do it, not even Safari and Edge, because plenty of people are forced to use Google services for work. At best, you would have a small number of people using minor browsers and passing around patches for major browsers to spoof the data discreetly.