It looks like that the Moto X won't be a successor to the Moto Z, but will instead be a midrange alternative.
The Moto X looks a lot like the Moto Z but from the renders, it seems that it will share the same design but differ in size as well as ports.
For some reason, the Moto X looks like it won't have a Type-C port and opt instead for the usual microUSB. As to the different size, it means that the Moto X won't be compatible with the Moto Mods. It's probably intentional to keep people buying the Moto Z instead of opting for the likely cheaper Moto X.
There's also a fingerprint scanner and the absence of certain trends, namely 2.5D glass and thin bezels. The lack of a Type-C port is a disappointment but it could have been a decision made to keep costs down and seems to be further proof the phone will be a midrange model.
If you're more in the market for a flagship, check out our review of the Moto Z, which features a series of Moto Mods.