If true, (but I highly doubt that they will arrest Trump), it would be done to try to stop him from holding the 3 July rally in Florida.
Ron Desantis will tell the feds and NY to pound sand if they issue an arrest warrant for Trump. And 10,000 angry rednecks with ARs will show up to guard him.
I predict people will die that day if they try it.
Or going to the border.