The rest of Josiah’s reign. In a sense he was greater than David. Certainly he was the most godly King since David.
It simply says he loved the lord with all his heart. And he leads the people in that love. So he actually does remove all worship of other Gods.
He celebrates Passover for the first time since time judges, pre the monarchy.
David, to give him his credit, couldn’t because the temple wasn’t set up.
There is a plan in this blessing of God’s I think. It’s setting a precedent for how the temple worship would operate post exile, though to Jesus day. It’s the true coming of monotheism to Israel. He makes a point of destroying the golden calf set up at Bethel by jeroboam, which reaches right back in tradition to the rebellion of the people in the book of exodus.
It’s a blessing to end the book on, the other end of the scale from Solomon, who squandered so much in a way.
And it really is end game after Josiah. Two of his sons become king in quick succession after he is killed in battle by the Pharaoh. The second son is a puppet king for Pharaoh, virtually his tax collector. Yes after rediscovering Passover for the first time in many years, they are slaves of Egypt again.