The part that is important is the captivity which isn't being freed from captivity. Present captivity! That remains to this day.
You said, "Are you familiar with the Hebrew idiom "bring again your captivity" or "return your captivity"? This doesn't mean going into captivity, it means coming out of it, back to their homeland."
Only the homeland part matches. You said captivity means not going into captivity but it doesn't mean that and Gill does not agree with you on that.
We are off topic so let's get back to Matthew 25 and Rev 20 etc.
This is part of the topic actually, showing Joel and Matthew to have these parallel passages.
but this designs the present captivity of the Jews, and the restoration of them to their own land; of which see Isa_52:8.
This part in red, you saw that, right?
To return their captivity is to restore them to their homeland. This is in complete agreement with the usage. These are just a few examples.
Deuteronomy 30:2-3 KJV
2) And shalt return unto the LORD thy God, and shalt obey his voice according to all that I command thee this day, thou and thy children, with all thine heart, and with all thy soul;
3) That then the LORD thy God will turn thy captivity, and have compassion upon thee, and will return and gather thee from all the nations, whither the LORD thy God hath scattered thee.
Psalms 14:7 KJV
7) Oh that the salvation of Israel were come out of Zion! when the LORD bringeth back the captivity of his people, Jacob shall rejoice, and Israel shall be glad.
Psalms 85:1-2 KJV
1) To the chief Musician, A Psalm for the sons of Korah. LORD, thou hast been favourable unto thy land: thou hast brought back the captivity of Jacob.
2) Thou hast forgiven the iniquity of thy people, thou hast covered all their sin. Selah.
Jeremiah 29:14 KJV
14) And I will be found of you, saith the LORD: and I will turn away your captivity, and I will gather you from all the nations, and from all the places whither I have driven you, saith the LORD; and I will bring you again into the place whence I caused you to be carried away captive.
Jeremiah 30:3 KJV
3) For, lo, the days come, saith the LORD, that I will bring again the captivity of my people Israel and Judah, saith the LORD: and I will cause them to return to the land that I gave to their fathers, and they shall possess it.
Jeremiah 32:44 KJV
44) Men shall buy fields for money, and subscribe evidences, and seal them, and take witnesses in the land of Benjamin, and in the places about Jerusalem, and in the cities of Judah, and in the cities of the mountains, and in the cities of the valley, and in the cities of the south: for I will cause their captivity to return, saith the LORD.
Joel 3:1-2 KJV
1) For, behold, in those days, and in that time, when I shall bring again the captivity of Judah and Jerusalem,
2) I will also gather all nations, and will bring them down into the valley of Jehoshaphat, and will plead with them there for my people and for my heritage Israel, whom they have scattered among the nations, and parted my land.
There are many more examples, and I think the best way to learn how terms are used in the Bible is to look at every place they are used. You have to want to do it though.
Much love!