Here is what i think : I guess, it is perfectly fine to use Amazon, as long as you don't use the Amazon feature which is known as Omakase, in which they try to figure out which ads to use by spidering your page.
In other context, we can refer it to as : other advertising is allowed along side adsense as long as it is not contextually based ads.

Also, another Adsense Term of Service policy to keep in mind is that, another ad service may not appear on the same site as Adsense if this other service looks like Adsense.

However, the Amazon doesn't look like Adensse, so it's fine.

[DELETED]