Sending a billing notification to someone who has no billing information on file, but is part of an organization where someone probably enabled that beta feature ("You're receiving this because your organization is using the GitHub
Code Quality public preview.") isn't a shakedown.
Did you even read the email? It's an extremely boring standard billing notification that explains exactly why that person received it "You're receiving this because your organization is using the GitHub Code Quality public preview." and when it would be come into affect.
It's not a small print somewhere, or one of these weekly app store subscriptions that run up high bills because someone clicked "Yes" in a game.
It's like calling a Netflix renewal email a "shakedown" just because they send you an email giving you a heads up that your trial will convert into a paid subscription.
You're making my point here - this sort of corporatist, bait-and-switch-if-you-dont-opt-out behaviour is illegal in many countries, Netflix got spanked for it this spring.
That featur is opt-in: someone had to check a checkbox somewhere to enable it.
And yeah, that how the businesses work: you opt-in to feature, then you start paying for it. Sometimes the latter part is delayed, in which case it's a good style to send heads-up email about it. Nothing unusual or scammy about it.