Can’t imagine why you aren’t getting responses – apparently everyone who has taken delivery of their new D7100s are busy taking photos. I still have my D7000, but here’s some information that I found. I come from a different point of view with the D800 and as you mentioned, expect the mirror to be up in Live View. So I would not be surprised if the newer cameras, like the D7100, work the same way.
Here’s a reference for the D7100, particularly the ‘Select live view photography or movie live view with the live view selector’ section that I was able to find