I feel like including ANYTHING aws-hosted muddies this up a fair bit. None of the other 5 are really hosting companies (and it sounds like they didn't block azure cloud or Google cloud? Not sure. They also certainly can't tell if something is AWS backed but behind cloudflare or other reverse proxies).

It's kind of like if they refused to go into a physical store because that store relies on AWS services to operate. Sure, that has ramifications of its own, but it's vastly different from using the services directly on your own, especially compared to, say, not using YouTube because alphabet owns it. Limiting the block to big-5 OWNED user-facing services would be much more interesting (and feasible) to me.