So, nope. Introducing security bugs and backdoors just makes it insecure for everyone.
There is also a black-market that can be even more lucrative. A bug could be jackpot for criminals.
See also https://en.m.wikipedia.org/wiki/Market_for_zero-day_exploits
So yes, I'm pretty sure that there are various teams, including white-hats such as Google, black-hats, nation-states such as China / Russia, analyzing each and every update.
There was also an interesting article on hackernews a while back demonstrating the technique, there are some nice tools for this. Sorry, can't find the link now.
But here's the fun part. Here are the corporate denials:
- Google: "We have not joined any program that would give the U.S. government direct access to our servers."
- Apple: "We do not provide any government agency with direct access to our servers."
- Facebook: "We do not provide any government organization with direct access to Facebook servers."
And so on. An exploit with plausible deniability enables these companies to make these comments completely truthfully, and at least mostly truthfully if they claim they are not providing a backdoor. But more to the point, there is absolutely no reason these companies would all say "direct access" as that's very specifically a subset of "access." If you do not facilitate direct or indirect access, why would you not simply say access? If this were a one-off thing, that'd be one thing since on occasion some PR is... odd. But literally all the companies were saying the exact same very peculiar thing. That's not a coincidence.
[1] - https://en.wikipedia.org/wiki/PRISM_%28surveillance_program%...