Why did the exiled northern ten tribes not need to return from captivity?
The exiled northern ten tribes did not need to return from captivity because a constant migration had already brought Israelites from the northern ten tribes down into Judah. By the time of the captivity, all Israel was representatively in Judah, so a return was unnecessary.
Les explains that by the end of the history of the northern ten tribes, they had become greatly depleted. In 1 Kings 20:27, the children of Israel of the northern kingdom were numbered and pitched like two little flocks of kids, showing they were not enough to even fool with. Les also points to 2 Chronicles 15:9 to prove a constant migration of Israelites from the ten northern tribes down into Judah. Therefore, what was taken captive did not have to come back because all of Israel was now down in Judah, at least representatively.
And he gathered all Judah and Benjamin, and the strangers with them out of Ephraim and Manasseh, and out of Simeon: for they fell to him out of Israel in abundance, when they saw that the LORD his God was with him.
More Questions
Why didn't the captured northern tribes have to come back after being taken captive?
Because of that constant migration, the northern tribes' captives did not have to come back after being taken captive, since all of Israel was already in Judah, at least representatively.