Yup. This move confused the hell out of me when I watched him give it. I was like "WTF, Trump? First you tell us all to make sure we're at the capital on this day, and then you turn around and tell everyone to go home??"

Had me pacing back and forth for a while. Then I read up on the Insurrection Act on wiki and read the section about how it can be "invoked." Light bulb came on... It can be verbally invoked:

Before invoking the powers under the Act, 10 U.S.C. § 254 requires the President to first publish a proclamation ordering the insurgents to disperse.

Yup