Luk 10:22 All things have been delivered to Me by My Father, and no one knows who the Son is except the Father, and who the Father is except the Son, and the one to whom the Son wills to reveal Him.”
The reference to children in verse 21 applies to the seventy missionaries. They are children in the sense of not measuring up to standards applicable to a good and righteous Jew. They were the sort of folks that gave Jesus a bad name among the scribes and Pharisees. They were commoners. Jesus said these low-life sorts had more insight into godliness than did the clergy (Luke 9:48; 18:15-17). Clergy, by comparison, tend towards pride in their theological knowledge and they are not open to learning from “children” in the faith (James 3:1, 14-18). This feature of the righteousness of the children is evidenced in their role in the dethroning of Satan (see also Luke 7:21).
Verse 22 flows topically quite nicely. Jesus did not agree with the scribes and Pharisees that he should minister to more suitable disciples. He chose to minister to people whom the Jewish leadership called “tax collectors and sinners” but whom Jesus called “infants” (see also in Luke 10:38-42 that Jesus gave personal undivided teaching attention to a woman). Jesus was told they were not worth it but Jesus ministered to them and they had a role in the overthrow of Satan.
The point of verse 22 is not that Jesus chooses to reveal the Father to some individuals and not to others. The point is that Jesus chose to reveal the Father to a certain sort of people, a kind of people that the scribes and Pharisees deemed to be religiously inferior. These disciples were working out to be very effective workers in the kingdom while the Pharisees stood by and criticized.