It does today, yet most of the top upvoted ones aren't from the last few years. Rather, most seem to be from 2 to 3 years after Victoria was fired. So they seemed to get more popular in the first few years after she was fired, and then less after that. I'm not sure that can simplistically be chalked up to an expanded user base.
The most upvoted AMA of all time is Obama's from a decade ago. However, that was a year before Victoria started working there (she only worked there two years from what I can find).
None of this is to denigrate her work, for what it's worth. Just that the doomsday scenarios that were given back then (IAMA mods were claiming they wouldn't be able to continue unless Reddit changed its decision) never came to pass.
The subreddit was a default subreddit for a while, and no longer is. So for some years, every new Reddit user was automatically subscribed to it, and that stopped being the case.
Everything you're saying is consistent with OP's claim.
It would probably be an interesting exercise to download the data for all the AMAs and adjust by MAU to see what the actual most popular threads were, but I'm not going to do that right now.