All this does is make Crooked Hillary look sophomoric. I'm sure Trump will make sure that this little prank is widely known between now and Monday night. So everybody will know ahead of time what asses they are being. Wouldn't be surprised if Cuban ends up backing out because this stunt can only reflect poorly on him. He's allowing himself to be used as a tool.
I can only imagine the media outcry if Trump was to give, say, Howard Stern a front row seat.