They are forever, contingent on Israel’s willingness to obey the Covenant, otherwise it impugns God’s trustworthiness.
Yes, God’s promises to Israel are forever - but the real question is, “who is Israel”? God treated Israel as “his wife”, protecting and providing for her. But she was unfaithful, and the “Nation” of Israel - and their temple - was utterly destroyed. However, a faithful ruminate remained and accepted Israel’s Messiah, and for 18 years this was the “church”, the bride of Christ. And all who accepted Jesus as Messiah - Jews at first and later Gentiles - were accepted into this new covenant.
The new covenant included us gentiles