I'm not sure he's ready to put that as a top priority in a speech that will be addressing more common global leader issues. I mean, sure, be might have if it weren't for "bigger" mainstream issues like the border, California fires, jobs, trade, and war's overseas. I think Bitcoin just gets lost in the shuffle and to announce it at inauguration is playing to a smaller (really) crowd where 90+% of Americans still have no idea. The media would have a field day. He's smart, knowing that his speech will be dissected and he'll play to the crowd giving them what they want.