As stated above, Jonathan Groff was the featured guest tonight. The end of the play is a sing-along with the audience, eventually asking for men to sing along, then women, then the Broadway Producers promised to be in the room at the top of the show. At this point, the guest, wearing a Producer trucker hat sings the line back to them, is introduced by Rannels as a famous Broadway Producer, and comes up on stage, to offer the duo a Broadway contract for this musical. Rannels then proceeded to kiss, extended on the lips, both Andrew and Josh, before walking off stage right. I was outside and saw Groff chain up his bike to the light pole out front, and head in the stage door about 75 minutes before the show, presumably to walk through what he needed to do. This is much more scripted than the celebrity guests at Oh Hello, with the dialogue on a prompter on the mezzanine rail, but my friend and I still can see people going to this multiple times to see what person pops up for this spot on a night-to-night basis.
I'm assuming the lead producer on the production did this on Friday night, since it didn't get any buzz-can anyone who was there confirm?
I'm not going to spoil what happens next, but just know that the set isn't all that it appears to be, at least for the last 30 seconds of the piece. And since the finale set change reverts back before the curtain call, so it isn't spoiled in curtain call photos/videos, I wasn't expecting it, and really liked it.