The FAA is in charge of Civil Aviation, not the FBI. A statement about this should have been made by them, with a simple "Yeah, we know about this".

It was! This was a joint statement including the FAA - also with DHS, the FBI, and DoD. The Biden WH took it seriously, had all those agencies that might have investigative oversight over a question of unauthorized or illegal aircraft, and had all of them issue a formal joint statement to tell everyone that it was all right and that "they know about this." It was a mix of stuff that files a flight plan with the FAA and all the hobbyist and recreational users that don't have to do that.

But because it was Biden, it had to be bad and wrong. Instead, the President has a conversation with the Press Secretary, who then informally advises the press that it was a mix of stuff that files a flight plan with the FAA and all the hobbyist and recreational users that don't have to do that. But because it's Trump, it's good and proper - and necessitates a ding at Biden for, I guess, making the mistake of having all those agencies announce their findings in a formal statement instead of being Trump and just discussing it informally with the press office.