John Gill Commentary 2 Kings 23:19

"And all the houses also of the high places that were in the cities of Samaria, which the kings of Israel had made to provoke [Jehovah] to anger, Josiah took away, and did to them according to all the acts that he had done in Beth-el." — 2 Kings 23:19 (ASV)

And all the houses also of the high places
The temples of the idols there, and the houses for the priests to dwell in:

that were in the cities of Samaria, which the kings of Israel had made
to provoke the Lord to anger, Josiah took away ;
particularly in the cities of Manasseh, Ephraim, and Simeon, unto Naphtali, (2 Chronicles 34:6) the Israelites that remained there acknowledging Josiah as their king; and perhaps, after the defeat of Sennacherib, many of the cities of Israel might put themselves under the protection of Hezekiah, and especially upon the destruction of the Assyrian empire;

and Manasseh, with his liberty, might have his kingdom enlarged by the king of Babylon; and which being continued and increased in the times of Josiah, might be the reason of his opposing the king of Egypt in favour of the king of Babylon:

and did to them according to all the acts that he had done in Bethel ;
defiled them, and broke down the altars in them.