First of all. The people who disobeyed in Noah’s day were judged by a RIGHTEOUS JUDGE.. Therefore is no reason for Jesus to have to go preach to them.
Secondly.. people miss the words “through whom” which tells how Jesus/Salvation was preached to them.
The Matthew Henry Commentary: 1 Peter 3:19 The preacher-Christ Jesus, who has interested himself in the affairs of the church and of the world ever since he was first promised to Adam, Gen. 3:15. He went, not by a local motion, but by special operation, as God is frequently said to move, Gen. 11:5; Hos. 5:15; Mic. 1:3. He went and preached, by his Spirit striving with them, and inspiring and enabling Enoch and Noah to plead with them, and preach righteousness to them
John Wesley’s Study: 1 Peter 3:19 By which Spirit he preached - Through the ministry of Noah. To the spirits in prison
The Bible Knowledge Commentary - by the Dallas Seminary Faculty - 1 Peter 3:19 The Spirit of Christ preached through Noah to the ungodly humans who…
Jamie