I went and looked at order confirmation emails from 2019 and confirmed my memory that back then they didn’t list what items I ordered (but did a few years before). At the time I figured this change was intended to fight against Paribus, a startup that would scan your email and automatically request compensation for late Amazon deliveries.

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.