The remnant of the nation that will receive the promises vs other individuals in that nation who do not receive the promises.
The promises are not invalidated because of those who do not receive them.
As one Jew who came to Christ relates about his mom, before she became a believer but after she had started reading the Scriptures for herself, she came to him in tears (IIRC how he related the story) having learned how the people had been warned in advance time after time.
Indeed, before there had been one exile we find a return from a SECOND being mentioned in Isaiah 11:10-12 and Israel the modern nation is now fulfilling to prophesy of the valley of dry bones even though they are collectively still at the stage where the bodies have flesh but not yet life.
Yet there is always a remnant.
As it says, the Gospel was given first to the Jew and then to the Greek (a type for all gentiles).
So the promises ARE forever.
Of course. The Apostles, their families, and many early disciples of Christ, were that Jewish remnant.
As for today's Jews, they are on the same footing as today's Gentile nonbelievers. All are free to accept Christ. The door is open to everyone. The choice is yours.