He’s right to talk about this. Since God has been pretty silent on this issue, why shouldn’t a man talk about it?
God is not now nor has He ever been silent on this issue, He predicted it.
1Sa 8:5 And said unto him, Behold, thou art old, and thy sons walk not in thy ways: now make us a king to judge us like all the nations.1Sa 8:6 But the thing displeased Samuel, when they said, Give us a king to judge us. And Samuel prayed unto the LORD.
1Sa 8:7 And the LORD said unto Samuel, Hearken unto the voice of the people in all that they say unto thee: for they have not rejected thee, but they have rejected Me, that I should not reign over them.
1Sa 8:18 And ye shall cry out in that day because of your king which ye shall have chosen you; and the LORD will not hear you in that day.