Looks like the American "red carpet" premiere should be happing in Chicago at an IMAX theatre on June 20th (just a day before the new release date of the 21st).

This is according to the IMAX competition conditions for North Americans to win a trip for two to the event, and spending 4 days/3 nights in Chicago. Although, according to the condition of the competition, they are only giving the winner two nights accommodation in Chicago... so I'm not sure what happens for the third night, or if they made an error there.

Transformers: The Last Knight is scheduled for theatrical release on June 21, 2017. The Premiere, if any, is anticipated to occur on June 20, 2017, but the specific date is subject to change. Nothing set forth herein shall be construed to require Sponsor to hold a premiere of Transformers: The Last Knight at any particular time, or at all. Once the Winner’s guest is designated, he/she may not be substituted, except at the Sponsor’s sole discretion. Transformers: The Last Knight is not yet rated by the Motion Picture Association of America. If the Winner is unable to participate in the Trip during the dates set forth by Sponsor above, the Prize will be forfeited in its entirety. In the event that the Premiere does not or cannot take place as scheduled or at all, for reasons included but not limited to scheduling conflicts, cancellations, postponement, or for any other reason, then in lieu of the Trip, the Winner will receive the remaining components, if any, of the Prize, which shall constitute full satisfaction of Sponsor’s Prize obligation to the Winner, and no other or additional compensation will be awarded.

One (1) Grand Prize winner will receive one (1) 4-day/3-night trip for two (2) people to Chicago, Illinois (the “Trip”) (Approximate Retail Value $4,000). The Trip includes round trip economy air transportation for two (2) from the major airport nearest winner’s residence to Chicago, Illinois, two (2) nights hotel accommodations (based on single room, double occupancy), ground transportation to/from area airport and hotel, one (1) gift card in an amount equal to US$500 and two (2) tickets to the premiere screening of the motion picture Transformers: The Last Knight (the “Premiere”)