It's definitely possible, but I don't think we can rule out the logical possibility that a language will typically only reference another language that came before it.

It makes sense, too- Considering a given language, another language that is much newer wouldn't have existed when the phrase was created, and a language of the same age or only a little newer, was probably not widespread enough to be referenced when the phrase was coined.

The notion of two existing languages as differing in age is problematic. They are ever changing. How do you compare the age of contemporary french to that of contemporary chinese? If you look at the list you see that it is always (except for the chinese) different language families meeting.