Well, how old was never specified. Remember, the setting was still yet completely set in stone during Season One, so maybe the writers decided to revise the founding of Ponyville to a nearer time.
How did you take the view that the ancient Equestrians might have expelled/exterminated the original inhabitants of the land when they first colonized the area around Ponyville and Equestria, as I implied with original commentary? It had happened before in real life with too many times to count, and since such practice was considered normal back then, I wouldn't put it past the ponies when they colonized Equestria. It does add a unique flavor to interpretations of the town's origins...