No. With something as important as a space launch, the idea of a 10-second abort based on a phonecall is crazy. They need to be sure it isnt disinformation. That late in the game i would expect all communications to be only from verified sources, sources on a list with dedicated pathways and roles. Millions, billions are on the line.

I have taken issue with musk tweets that have been less than accurate before. Time will tell.

It doesn't cost nearly millions or billions to scrub a launch... It definitely costs that much to have a failed launch.

He was on site with engineers. This is such a bizarre thing to be doubtful of.