Nashville Chatter Class claims it has been able to pick up at least the Indonesian and Thai records for the Moto E5, Moto E5 Play, Moto G6, Moto G6 Plus and Moto G6 Play — internally, they are named XT1924, XT1944, XT1925, XT1926 and XT1922.
A previous leak of a presentation deck indicates that all of the G-series devices will be getting modern applications chipsets in the Snapdragon 400- and 600-series. All of them will have 2:1 displays and some will have fairly advanced memory specs as well. Not much is known about this generation of E devices.
With recent rumors claiming that the Moto X5 will be forever stuck in development hell, it seems as though there will be no mid-to-upper tier device to fit in the gap between the Moto Z3.