I saw screenshots of the event temporarily being listed on the Passholders Events page on a WDW Passholder Facebook group this morning before that site posted about it. It's limited to Gold Passholders and higher.
I did the tour a few weeks ago. We walked around the outside and the tour guide discussed the Imagination Pavilion for a few minutes, but we never went inside. The VIP lounge we went into was the Test Track lounge.