A quick scroll through the schedule doesn’t indicate any “A-level” or “A+ level” Broadway talent participating in talks/performances/signing sessions (people like Peters, LuPone, McDonald, LOJr, Platt, Idina, Gad, Rannells, Lin, Groban, etc).
There doesn’t even seem to be much Broadway “B-level” talent (people who’ve been nominated for or won Tonys and had some level of crossover success outside of the theatre but aren’t selling out a show on their own (Donna Murphy, Megan Hilty, Roger Bart, Shoshana B, Josh Henry, BVD, Jessie Mueller, Annaleigh, etc)
Some of these autograph sessions appear to be with people who’ve worked in the ensemble or replaced in supporting roles, which if continuing the above metric would be lower than Broadway’s D-list, as far as drawing power is concerned.