Board Thread:Suggestions forum/@comment-26429944-20180208085334/@comment-26298013-20180216165152

Not necessarily. Had they rejected the worship of Melkor they may not have allowed their blood to dwindle, or perhaps they would have sailed to Gondor and professed allegiance to the King, etc. etc. They might, MIGHT, have become "regular" Numenoreans after revoking Melkor, but the reason the "regular" Numenoreans didn't fade is because they intentionally kept their blood pure(ish) and also because they held to the "correct" path, loyalty to the King and Eru Iluvatar. So if a Black Numenorean "redeemed" themselves, then yeah, they'd PROBABLY be "Numenorean". Similar to how Aragorn's rekindling of the Kingdoms of Gondor and Arnor granted him longer life/greater kingliness/name-your-Numenorean-blood-advantage, I suspect a Black Numenorean who "redeemed" themselves in this way would reclaim some of the life of a true Numenorean, though likely not all of it.