Sounds like modern atheist revisionists trying to still fit in their old earth fantasy which is rapidly collapsing under its own weight and the weight of the real evidences. All dates for anything past 5000 BC are arbitrary guesses typically founded on either 1. Disproven techniques like radio-atomic dating or 2. Unproven or disproven theories such as evolution, cultural evolution, etc. which are essentially defunct now due to the increase in knowledge which shows a more robust and active past of human history.
Hard supporting evidences and logic for Jericho indicate it was destroyed in exactly as manner described in Book of Joshua as well as evidences that show it was rebuilt (which is supported also by the biblical Books of Kings.) There is only hard proof for one age of Jericho pre-Joshua in which it was inhabitted by the Canaanite Race which is supported well by Genesis and the other books of the Torah and the later histories of that time era like Joshua.
Since the only hard, non-theoretical evidence and history that exists in this current time show inhabitation by Canaanites, that Jericho's walls were indeed destroyed by God during time of Joshua in exactly the manner the book of Joshua describes, and since we know the Canaanites dwelt in the Levant after the dispersal of nations we can logically conclude Jericho first came into existence also sometime between post-Tower of Babel and pre-Joshua. Additionally we know that Jericho could have only existed post-Flood since Canaan, the namesake and patriarch of the Canaanite race did himself not even exist until after the Flood.