I highly doubt this story. For a lot of reasons, but let's say the FBI did this above board, an assumption, I know, but if it wasn't above board, I think Meadows or his lawyer wouldn't go through with it.

There is a long standing DOJ Office of Legal Counsel memo going back to Watergate days that says a sitting president can't be indicted.

In 1973, the Department concluded that the indictment or criminal prosecution of a sitting President would impermissibly undermine the capacity of the executive branch to perform its constitutionally assigned functions. We have been asked to summarize and review the analysis provided in support of that conclusion, and to consider whether any subsequent developments in the law lead us today to reconsider and modify or disavow that determination.1 We believe that the conclusion reached by the Department in 1973 still represents the best interpretation of the Constitution.

https://www.justice.gov/d9/olc/opinions/2000/10/31/op-olc-v024-p0222_0.pdf

That seems like a very big obstacle to this. Is this the sort of thing I judge would be needed to sign off on? That seems like a very big ask.

Could Meadows have made recordings on his own? I don't know if doing that with the President or in the White House is legal, but in general DC is one-party consent....meaning it's legal to record your own conversations with anyone because you yourself "consent' to the recording.

DC Wiretapping Law

The District of Columbia's wiretapping law is a "one-party consent" law. DC makes it a crime to record a phone call or conversation unless one party to the conversation consents.