IA was not served with a court order; Reuters was (in India).
(It would still be voluntary even if IA had been ordered to do something in India, because as is the topic of the thread, IA is a US-based nonprofit under the jurisdiction of US courts).
So, deciding not to comply with the norms of foreign jurisdictions is a risky business. Aggrieved judges from other jurisdictions can and will do things that will make your life miserable-- seeking to seize foreign assets, filter locally, arrest your personnel when they travel there, etc. So just ignoring any action that might happen in India isn't really an option.
Of course, letting the most restrictive jurisdictions set the global norm isn't great, either.
Anyways, I fully understand how one would make the choice to not piss off India. From your source:
> "We were faced with the decision of either keeping the article available and risking having legal action taken against us, and incurring a costly defense in an unfamiliar venue..."
That's under duress and coercion, and doesn't meet my definition of "voluntarily", even if one could still fight.
