The context was a
Trump Youth Turning Point USA rally, so they probably got the message loud and clear:
I wouldn’t be surprised if Trump doesn’t specifically know what this gesture means, but that has been told by somebody cough Miller cough that it’s a good way of firing up the base.
It doesn’t really matter either way.
The battle against Trump is a battle against white supremacy, and anyone who denies that is either a liar or a fool.