Missing the context... What code was there before? Was it a reverse engineering of the API whatsapp binaries use? Is there any legal basis for demanding someone remove that?
It's not well-known, but if you use "git clone --mirror" instead of just "git clone", you get a copy of all the pull requests as git commits, with the full history leading to each of them.
Actually these libraries are used by third-party clients on platforms that Whatsapp doesnt officially support such as webOS, Firefox OS and others. Its not about spamming, its about being able to offer a decent client on platforms that are not covered by official clients.
Does the library enable the service to be used on more platforms? Yes. Does the library enable spammers to abuse the service? Also yes. It's not an either/or situation.
A library is just a tool, like a hammer, you can build a shelf with it or hit your neighbor. anyway, you don`t solve that problem by banning hammers....
I don't think there's a legal basis for preventing someone from reverse engineering an API in general.
The "non-circumvention" clause in the DMCA is often used to go after people reverse engineering DRM, but I fail to see how it would be applicable in this case.