They did, though it's hard to trace when exactly this happened. The focus of our sources shifts away from the small cities and onto the larger Hellenistic kingdoms and states, and we lose track of detailed developments within the communities once famed for their hoplites. We know that some of them (especially Sparta) eventually switched from hoplite infantry to Macedonian pikemen, and that the 3rd century BC saw the spread of the new Celtic thureos shield which replaced the old hoplite aspis, but for most communities we just don't know how their armies developed. The military traditions of the Greek states finally die out when they are subjected to Rome, which meant they no longer had armies or foreign policies of their own. I answered this question in more detail here.