No, sorry, this is a positive change that was overdue for years. Gmail (and likely other email providers) was scraping the contents of the email to build a list of your purchases and it was not possible to delete items or clear it.
By this logic, nothing can ever be shared by email. Else someone (user included) might scrape some value from it.
If it is truly for my benefit, they could let me opt in or out of the behavior. I truly derive value from being able to search the local copy of my email to track purchases.
What's the purpose of the emails then?
It’s my choice to use (or not use) Gmail. What data I share with them in exchange for their service is non of Amazon’s business. (If Amazon wanted to make this feature opt-in, sure, whatever.)