Instagram's TOS before these sweeping, far-reaching changes was already hostile to photographers. You granted Instagram a transferable, sub-licensable, perpetual license that has no expiry or termination condition, ever the moment you uploaded something.
The terms of the license you grant Instagram is about as broad as it gets, and reaches substantially further than just about any reputable photo sharing service out there.
For example, Flickr and 500px's TOS gives them license only as long as you hold the account and the image hasn't been deleted. Deleting your account or the photos themselves is revocation of their usage rights. Instagram is bound by no such rules.
By posting to Instagram before the new TOS NatGeo already exposed their photographers to tremendous IP risk - one can only hope NatGeo themselves hold the right to grant an irrevocable, perpetual, sublicensable license to the photos in the first place.
I'm glad to see companies with photographer-hostile TOSes getting called out for the tremendous overreach in their legalese, but this isn't really new, Instagram was like this from the get-go.