Like you I wondered if they would ever show him. CBS is doing all they can to be sure no one would even know the President is there. I remember when Obama was there they showed him constantly - eating, chatting, whatever. My family is there and said he got a great welcome and everyone is very excited that he is there.
I have watched many Army-Navy games on TV. I do not recall ever seeing a series of videos of previous presidents during the coin toss, or at any other time during the game either. Two years ago, when Trump was President-elect, during halftime, he chatted with two of the announcers, one of whom had been a good friend for many years. That was during a very hopeful time and showed how personable Trump really is. I wonder if even that announcer has become a hater.