The Louisiana Governor had control over HER guard. Calling in other states' guards must be done by a formal request to the President, which hadn't happened until Thursday.
I don't know what the actual protocol is, and have read that state-to-state pacts exist.
Clearly, "calling out the Guard" is not a one-size-fits-all proposition. The NG may be called to search people entering the SuperDome, or it may be called to quell insurrection. Blaco did call for something on Thursday, but I don't know exactly what that was.
I'm sure you saw that the President is now sending in 7,000 active duty troops.