It's really the same people almost every year at every show. With the exception of their huge shows (Chicago, etc.), you will find the same people pop up throughout the year outside of other commitments.
I've noticed that among the second- and third-tier guests. It still looked like up until 2018, WW was able to bring new top-tier guests every year.
In retrospect ... it seems like 2016 was kind of a luck-out for Wizard World New Orleans. That was a Murderer's Row of guests (esp before cancellations) -- and since that was our first WW con, we thought that was typical. 2017 wasn't too far behind before Carrie Fisher's passing. 2018 still had Stan Lee (who could be a one-man con, really). After that, though?