Does the Pasakh Controversy Prove Sunday Pasakh Was Not Universally Observed from the Beginning?

Evidence: Eusebius, Ecclesiastical History 5.23–24 · 2nd c.

What the ancient record says

If every assembly had always followed the same Sunday-based Pasakh from the earliest period, there would be no reason for the controversy, but there was one: Asia kept the fourteenth day, others differed, Rome tried to force conformity, Polycrates refused, other leaders intervened. Establishes at minimum that 2nd-century practice was not universally uniform (historically unavoidable).

Does not prove every assembly originally observed the fourteenth day, that needs more evidence; Polycrates gives important testimony for continuity in Asia and names earlier figures, but regional variation is what the evidence demonstrates. Two myths to avoid: (1) everybody always observed Sunday Pasakh (the controversy contradicts it); (2) we can prove every assembly always observed the fourteenth day (evidence does not establish it).

Provable: the fourteenth-day observance was old, established, widespread in Asia, and defended as inherited tradition.