The list below is now out of date. An updated list can be found here.
Here is a photo of the current free show list for Total Rewards Diamond and Seven Stars members. Shows are 2-for-1 for Platinum players. The most notable change is that Penn & Teller is no longer a free show option.
The Penn & Teller information I was given was misleading. It is still officially on the list, however, the free tickets have been sold out for weeks are unavailable for the near future.
I have received multiple confirmations that Penn & Teller tickets are available again as part of the Diamond and Seven Star Free Shows.