A man of God foretold that a son of David would burn bones on Bethel's altar. What was his name?

Answer: Josiah

He named Josiah long before his birth. 2 Kings 23 records Josiah burning bones on that very altar at Bethel to defile it.

“And he cried out against the altar by the word of the LORD, “O altar, O altar, this is what the LORD says: ‘A son named Josiah will be born to the house of David, and upon you he will sacrifice the priests of the high places who burn incense upon you, and human bones will be burned upon you.’””— 1 Kings 13:2 (BSB)