I was at D23 all 3 days as well. Sadly I missed the meetup (I also managed to miss the Agents of Shield preview) it was a great time and I also will be back in 2 years.
Agreed the Red Shirts at the Expo were almost Useless, I got in the habit of looking for someone with a Disney name badge if I had a question. I asked one red shirt where the "Talent Roundup" was and he said he didn't know. Someone tapped my shoulder and pointed up. The gent in the red shirt was standing under the Talent Roundup sign.