I'll take a guess at what he means by Protestants following papal authority every easter.
Protestants follow the date for easter defined and changed by pope Gregory XIII in 1582, instead of the one used by all Christians for the first 1500 years.
Actually, I just meant that every Easter lots of Protestants convert to Catholicism. We have a formal program of study which culminates in Confirmation and (for some) Baptism on the Easter Vigil.
But you make an excellent point. Not even the Gregorian calendar, but the setting of the date for Easter and the very idea of celebrating Easter are from the Catholic Church's mandate.
SD