In A Commentary on the New Testament, published by the Catholic Biblical Association in 1942, pages 119-120, says, in part:
28. *… *The Son of Man coming in his kingdom: cf. the variant expressions in Mark and Luke. It is not certain what this refers to. Some of the Apostles will see it; others will be dead before that time. It cannot refer to Christ’s coming at the end of the world when all the Apostles will long since have been dead. Nor can it refer to some event in the near future, such as the Transfiguration, Resurrection or Ascension. For all of the Apostles lived to see these events, which moreover do not contain the element of retribution demanded by the context. It probably refers to the destruction of Jerusalem [in A.D. 70] in which Christ vindicated His honor by punishing the city that slew Him. The destruction of Jerusalem is a type of the destruction of the world on the last day; as such, the expressions which refer properly to the one are also used analogously of the other. See Commentary on [Matthew] 24, 15-35.