Unsurprising

“ALVIN: I AM GOING TO KILL YOU!!!!!!!!!!!!!”″ said the typewritten note in a letter contained in an envelope addressed to Bragg, WNBC reported, citing law enforcement sources.

The letter, containing an Orlando, Florida, postmark from Tuesday, was found in the DA’s mail room in a lower Manhattan building after being received at 11:40 a.m. ET on Friday. The white powder in the envelope was found to be non-hazardous, the New York Police Department told CNBC.

[...]

The threat to Bragg is one of several hundreds that have come in recent weeks as the DA’s office nears the end of its investigation of Trump, a senior New York law enforcement official told WNBC. A couple of dozen were considered to seriously threaten direct harm to Bragg, though their credibility varies, according to the official.

Security officials are closely watching the threats and investigating.

  CNBC

Since the letter was sent from Orlando, the fact that it was received hours after Trump's specific threat of "death and destruction" is coincidental. The point here is rather that these threats to Bragg and others pursuing Trump's criminal activity are ongoing as Trump continues to make inciting posts and speeches.