In the previous post, I suggested that the parable of the wicked tenants is the culminating point of Jesus' criticism of the priesthood, of which the priests became well aware (Luke 20.19). I believe that in the Gospel records, Jesus' final speeches bear enourmous weight. (Recall my comment regarding Luke 24.50-51.) Just before the process of his arrest, trial, death and resurrection in the Gospels, Jesus is recorded as packing everything he has previously taught into tight speeches (see esp. John 12, which contains elements of every episode of Jesus' life and teachings up to that point; see also Matthew's Olivet discourse). It's as though he's trying to give his followers a final word in hopes that they'll remember everything - sort of like a farewell under fire, though not so nervously. But the information relayed by these writers comes as most urgent, even neglecting any narrative signposts (as in John 14-17, which contain no setting indicators whatsoever).
I see Luke progressively growing his story in this kind of direction, beginning in ch. 14, and culminating in 21, closing with a word of his coming. Luke 20.46-47 is a magnificent example of this phenomenon. Note the parallels:
20.46 // 7.31-32 = The scribes and Pharisees love the market places and publicity.
20.46 // 14.7-11 = Pharisees love places of honor.
20.46 // 11.43 (7.31-32?) = Parisees love the best seats in the synagogues and salutations in the marketplace.
20.47 // 21.1-4 = The widows in poverty are vidicated against their adversaries.
20.47 // 18.9-14 = Pharisees love long prayers.
These parallels perhaps indicate what Jesus' emphases were throughout his ministry. Luke 20.46-47 then would be a brief synopsis of important themes in his teachings - important enough to merit mention at this point in Luke's story. He then moves to topics of his coming and the temple's coming destruction.