While this needs a whole essay, here is a new quote that gives focus to the issue.
The immediate topic is Matthew 28:19.

The Resurrection and Modern Thought (1915)
William John Sparrow-Simpson

(3) The omission of the Baptismal Formula may be due to that instinct of reserve and reticence (the disciplina arcani) which was elevated into a principle by the early Fathers of the Church.1 Certain critics have treated this explanation with contempt, but it is sufficient to read S. Cyril of Jerusalem to see that such contempt is entirely out of place.

Cyril of Jerusalem says,
“To a heathen we do not expound the mysteries concerning Father, Son and Holy Spirit, nor do we speak plainly of the things touching the mysteries in the presence of catechumens; but we often say many things in a hidden fashion, in order that the faithful who know may understand, and that ‘those who know not may not suffer harm.”’2

1 Riggenbach holds this.
2 S. Cyril of Jerusalem, ‘Catech.’ vi. 29.