To be clear, tech companies provide subscriber metadata (e.g., billing address, real name) with a court order or subpoena. They provide actual user data (e.g., voicemail) only with a warrant.

Or has something changed since the last time I requested user data from a tech company by subpoena? Or are you talking about intelligence collection as distinct from law enforcement?

Also worth noting that LE frequently has PC without having a warrant (for example: every time they ask a magistrate for a warrant and secure one, we can infer they had PC first). In fact they perform many searches with only PC (see: exigency, eventual discovery, etc).

It would be more apt to say any subscriber metadata Apple knows, the FBI can know without a warrant.