For some reason, last year they did 2, only one month apart, in February and March. Most likely due to the onset of the pandemic.
This is definitely the season for it (February-March). The fact is, there is nothing on their schedule, March is over, and AMCAS opens in a little over a month. You can call AAMC and find out for sure, but my bet is it isn't happening this year, certainly not between now and June. If I had to guess, I'd say that's because schools were distracted by the delays in the cycle caused by the massive increase in applications and operational issues caused by having to move the cycle virtual, and they had no interest in planning for or staffing the event while they are still planning interviews and running their cycle.
TBH, as you know since you attended last year, it's really just the same questions, over and over and over again, in each and every school's room, and I didn't see a single question that couldn't be answered by looking on the school's website or asking someone on SDN. I also attended last year (both times) and honestly, after attending, don't feel like I'd be at a disadvantage if I never attended. That's probably because I spend way too much time on SDN, so I see how there could be some value to having a bunch of schools answering questions at one time in one place for people who aren't otherwise plugged in, but I don't think there is any added value for anyone who participates on SDN.