What does it take to read someone their Miranda rights? 20 seconds? The dude has been in custody for hours and they simply said he won't be read them at all. It's not a safety issue at all.
No. They have those rights whether or not the police remembers to verbally inform the suspect.
The suspect has every right to remain silent and every right to an attorney, even if the officer detaining him chooses not to remind him about it.
"The Supreme Court ruled Tuesday that a criminal suspect must explicitly invoke the right to remain silent during a police interrogation, a decision that dissenting liberal justices said turns the protections of a Miranda warning “upside down.”"
This decision doesn't refute the parent poster's point. The suspect always had the right to remain silent and the right to an attorney. The decision just affirms that you have to explicitly stop the questioning by speaking your intention of that. The minority felt 2 hours of silence and badgering by the suspect indicates a wish to stop the questioning and invalidate further coercive measures to extract testimony.