WhatsApp wants to do this as a means of providing you with a contacts list.
I rarely use the app, but I've had to use it a few times to get in touch with folks in other countries. But grant WhatsApp access to my contacts? Not a chance! So unfortunately I've lived with half a dozen unlabeled chats in the app that I just know who they are.
So in my particular situation, I think I welcome the change the Apple has made - I am fine with selectively granting a few contacts to WhatsApp (since those other folks already added me and chatted to me), so now I can put a name on those chats.
A good friend of mine has been in the paper industry for many years now. I've asked him this question specifically about pizza boxes:
When wood fibers get saturated with oil it's not really a big deal because oil is hydrophobic and fiber is recycled and purified through aqueous means i.e. flotation tanks that remove dyes, inks and oils etc. So fear not... that greasy pizza box is 100% loblolly pine with a little smattering of vegetable oil. It would happily be recycled.
New York... when civilization falls apart, remember, we were way ahead of you. - David Letterman