I would guess its this story https://www.nytimes.com/2021/06/10/us/politics/justice-depar...

But that doesn't match OP's description very well. It was a grand jury subpoena and only for metadata.

"As the Justice Department investigated who was behind leaks of classified information early in the Trump administration, it took a highly unusual step: Prosecutors subpoenaed Apple for data from the accounts of at least two Democrats on the House Intelligence Committee, aides and family members. One was a minor."

"Apple turned over only metadata and account information, not photos, emails or other content, according to the person familiar with the inquiry."

So they turned over the conversations but not emails. How does that not match? Meta data is widely used political a euphemism for this.

I'm not sure what you mean by conversations, if you mean the content of messages then no that is not metadata, if you mean who talked to whom, then yes that is metadata.