This matter concerns tracking within iOS apps. Apple has nothing to do with the "Ad Choices" program or anything else to do with website advertising.
I do not know this company, Amplitude, and never consciously gave them permission to use my Apple IDFA or combine it with my browser cookies, yet I don't doubt they have an accurate combination of those about me and sell it to any client who can afford it. And that is what this article is about: Apple is enabling this at the source.
There are undoubtedly many more Ad-tech companies who market data they gathered about me without freely given consent. Again, it needs to stop.
It's worth noting that Apple has already chosen to kill off IDFA (something that was created as a transition away from developers having to the device's raw UDID) and Apple took this step without needing to be pressured by consumer rights groups.
You should read again. Under "Determining Unique Users" you can see they link every "device id" to a unique user ID. A device id can be a browser cookie, an Apple IDFA or an Android AdID.
> Apple took this step without needing to be pressured by consumer rights groups.
Well, Apple is a smart company and better than most others with privacy. They may have concluded for themselves that they would probably get under pressure for this.
IDFA is not available in Safari at all. The api is available only to App Store apps.
IDFA has nothing to do with browser cookies and is not combined with them.
Especially never talk to any ad-tech companies. They are worth billions, but really do not offer anything on top of what Apple and Google have in their docs about advertising.