I cannot speak to him specifically, but one Ivy coach shared that they did not put their names at Showcases, or if they did add their names, they did it after the Showcase started. They wanted players who wanted them, and they wanted to avoid the hundreds of emails from players with a 3.0 GPA who had no chance of getting in to their university. I also know some coaches let their assistants put their names in at the showcases and get the flood of emails. They may have been there, but then they didn't have to deal with all of the emails from players.
Again, no idea if he is attending or not, but I would not assume he is not just because he is not listed. We always sent emails to coaches whether they appeared on the list attending or not for her target schools. And we always included the head coach in any emails about schedules-- even if they had one assistant who did most of the recruiting for them. Good luck!