In all the verses you quoted "αἰώνιον" is paired with πάσας τὰς γενεὰς which proves that αἰώνιον means eternal, everlasting etc.
"εἰς πάσας τὰς γενεὰς ὑμῶν· νόμιμον αἰώνιον/unto all the generations of you a law forever." In this passage aionion is paired with "unto all your generations." which defines aionion as eternal. This was addressed specifically to Israel, all their generations forever.
Gentiles may choose, but are not required, to observe this requirement since it was directed specifically to "all your [Israel's] generations."
Well to avoid confusion I would just add this reminder that YHWH's renewed covenant is with Israel; and Yahshua was commissioned only for Israel. If one isn't grafted into Israel; then Yahshua wasn't commissioned for him; and he has no covenant.
(CLV) Mt 15:24
Now He, answering, said, "I was not commissioned except for the lost sheep of the house of Israel."
(CLV) Hb 8:10
"For this is the covenant which I shall be covenanting with the house of Israel after those days," the Lord is saying: "Imparting My laws to their comprehension, On their hearts, also, shall I be inscribing them, And I shall be to them for a God, And they shall be to Me for a people.
(CLV) Num 15:15
As for the assembly, there shall be one statute for you and for the sojourner sojourning with you. It shall be an
eonian statute throughout your generations. Like you so shall the sojourner be before Yahweh.
(CLV) Num 15:16
One law and one custom, it shall come to be for you and for the sojourner sojourning with you.
(CLV) Ex 12:49
One law shall there be for both the native and for the sojourner sojourning in your midst.
(CLV) Lv 24:22
The same judgment shall you come to have; for the sojourner as well as the native shall it be: for I, Yahweh, am your Elohim.
(CLV) Num 15:29
For the native among the sons of Israel and for the sojourner sojourning in their midst, one law shall apply for you, to anyone doing it through inadvertence.