Is there anyone whose waitlist didn't get cancelled? I can understand cutting people off from the waitlist if it is already way too long for the allotment that Sideshow will receive; but if every waitlist request got cancelled, then I'm confused.
One idea is that Hot Toys is actually adapting and starting to lower its production runs after a bunch of overproduction, but even then, Sideshow knows that not every preorder will result in an order, so a waitlist still becomes necessary.
The only way any of this makes sense is if there are still people on a (shorter) waitlist, with a chunk of the people at the end being taken off the list because there's little chance of them ever getting a conversion (e.g., number 4000 on a waitlist for 200 figures).