They have said this to the press or to the court? Because it seems to me like Fb/Whatsapp have been pointedly ignoring the courts for months. The least they could do is fly down a lackey to Brazil and say it in person and/or alternatively hire a Brazilian law firm to represent them.
I'm not sure what you're proposing Facebook to do here? Hand over useless encrypted data? Hold a cryptography seminar for Brazillian law enforcement to explain what end-to-end encryption means? Have more of their employees risk arrest?
Some more subtle hints may work better, but generally, what Facebook says, "it can't be done" is the correct strategy.
What lackey is going to want to fly to a hostile country where the government is battling your employer?
I don't want to spend any time in a foreign prison. Who would?