Further to previous replies, I would mention that Oxford still identifies its terms by reference to the Church calendar - Michaelmas, Hilary and Trinity.
Also many of the things Esty refers to are not exclusively Catholic.
While protestants have a different perspective on sainthood, saints are not ignored.
Here are some of the Saints days marked by the established church
and most Anglican Parish churches will have a patronal festival to mark the day of the saint to which they are dedicated. I have celebrated Candlemas a few times but admittedly in churches that belong liturgically in the "I can't belive it's not Catholicism" wing of the CofE.
Parson in modern England would not be used to refer to a Catholic priest. In this historical pre-reformation context it means that he was the incumbent of a church independent of the the control of a monastery or similar (unlike a vicar).
I just think he is using a historical context rather than making a religious point. After all church going was only at the beginning of it's decline when Farmer Giles was first published.