The purchase/shipped/etc email was the lifeline to tracking your Amazon spending and exactly what you bought. Now that is impossible. It's similar to a business refusing to give you a proper receipt and should be likely illegal.
What 3rd party companies I let hoover up my Amazon purchase emails is none of their business.
But then I looked at emails last year and Amazon was sending item names after order again. So it seems like this practice has changed multiple times.
At the time it felt like a specific reaction to Shopify mining this information to compete. (I have no insider knowledge if they were or were not).
Of course, the answer can be many things -- now it's AI, back then it was 17track, Google, Shopify, etc.
I've taken to screenshotting the initial shipping date, but it doesn't make much difference. I don't know what "Prime" even means anymore.
And I live in SF so it's not like there is some logistics problem with my location, either.
I noticed many Amazon emails, not just the 'ads' but also the order confirmation, order shipped, rate your order, etc emails related to a purchase. Honestly, never look at any of them because I know most will arrive either same day or within the next 1-2 days and I don't care for rating my orders.
It's only when something hasn't arrived within that timeframe that I check the app/website, both of which are much more useful.
I recommend stop feeding the beast. Have not used Amazon in 10 years and never will. They are so big that they harm the buying power of the consumer and selling power of the producer. Personal knowledge gained while working with them.