Sorry but I don’t believe in modern day prophets. If God is going to reveal anything he will reveal it to us ... otherwise it’s all noise just for hits and clicks!
I don't know who Charlie Shamp is, so I'm not commenting on anything he has claimed.
What's the interesting connection is that Jonah said that Nineveh would be overthrown (overturned, turned up-side down) in yet 40 days. He didn't say, "Repent or else Nineveh will be overthrown in yet 40 days..."
Yet no one would say that Jonah was a false prophet, and Nineveh did fall eventually. There are many commentaries on the subject. I'm just pointing out the basic info, especially in light of it all together with your post, like this:
Matthew 16:4 A wicked and adulterous generation seeketh after a sign; and there shall no sign be given unto it, but the sign of the prophet Jonas. And he left them, and departed.
Or this reference. People can get downright ugly in arguing over the meaning of that timeline.
But back to:
Jonah 3:4-5 And Jonah began to enter into the city a day's journey, and he cried, and said, Yet forty days, and Nineveh shall be overthrown. 5 So the people of Nineveh believed God, and proclaimed a fast, and put on sackcloth, from the greatest of them even to the least of them.
The people of Nineveh believe God and then acted accordingly. They got their act together finaly. That is to say, that *wicked* place was indeed overturned, as Jonah prophesied.
There's always a simple meaning at the end of the trail.