"Furthermore, the Court FINDS suppression unwarranted because the Government did not need a warrant in this case. Thus, any potential defects in the issuance of the warrant or in the warrant itself could not result in constitutional violations".
This language is particularly specific and narrows the ruling to this case and only this case. The fact that the FBI got a warrant to allow them to run remote exploit code on an individual's computers that had downloaded the exploit (which was only available on PlayPen) means that they didn't need a warrant.
The individual was exposing himself to this exploit of his own actions, and thus didn't require a warrant. Let me put it this way, the FBI takes over a drug dealer, and has him continue sale, but under the new watchful eye of cameras that collect identifying photos of individuals who purchase drugs. (Not only that, but the person has to go into a room that specifically says, “illegal drugs” on it in order to even end up on camera.)
Do law enforcement REALLY need a warrant when the person is incriminating themselves?
This is like arguing that law enforcement had no right to put a tracker in the cash bag of a bank that they took. It's BS. It required active agency in acquiring the exploit code, and a clear intent to obtain child pornography.
a) You do not have a reasonable expectation of privacy when you're committing a crime, and b) if you walk into someone else's house and demonstrate direct intent to commit a crime without knowing that you're identifying yourself to police, well, TOO BAD