When the new Moto Z and Moto Z Force were revealed, there was some palpable concern that the line would be a replacement (or renaming) for the Moto X line — but that apparently isn't the case. According to a statement from Motorola, the Moto X brand "is alive and well."
Speaking to Android Police, Motorola states:
Moto X is alive and well. In fact, Moto X Force recently launched in multiple new markets around the world. Moto X and Moto Z do share some great qualities, but they ultimately provide different experiences and make our portfolio more robust for consumers looking for the perfect smartphone to fit their needs. Tech-hungry consumers who are looking to get a brand new set of experiences from their smartphone will turn to Moto Z and Moto Mods.
To be clear, Motorola's comments only confirm that the Moto X line is currently living on in the form of 2015's releases; there's no explicit confirmation that a new Moto X is on the horizon. However, it's also possible that the company may be positioning the Moto Z and Moto X lines to coexist with some overlap.