I called earlier and my switch from non-exclusive to exclusive went through fine. So, hurrah, I'm getting the exclusive! The Sideshow person also mentioned that they'll be starting to authorize credit cards for Lara "in the next 2-3 business days". Seems like they were a little premature with their processing alert email...
I also think that in cases like these, where there are extra exclusives, they have exhausted the wait list, and the regular versions are all on wait list status or sold out, they should either offer the exclusive to those with a non-exclusive order, or have some kind of option when you place the order on a regular to automatically upgrade you to the exclusive if the situation arises.