The Invite states "get ready to shatter your expectations", and perhaps this is a reference to the upcoming Shatterproof Moto Z2 Force.
Motorola is due to launch five smartphones including the Moto G5s series, Moto X (2017), the Moto Z2 and Moto Z2 Force. That said, the upcoming smartphone may be one from the Moto Z2 lineup.
Maybe Motorola is looking to announce the Moto Gs series, or it maybe the Moto X (2017). That said, nothing is known for now from the company, and just a few days to go for the Official announcement of these devices.