Good afternoon

Hello Rabbi,
In Isaiah 7:8 it is said: "For the head of Aram is Damascus, and the head of Damascus is Rezin; and within sixty-five years Ephraim will be cut off from the people."
According to the literal interpretation of the verses, it appears that Isaiah is speaking to Ahaz about an event that will happen in 65 years, but in reality the exile of Samaria occurred about 12 years later.
Sages and commentators link the number 65 to the prophecy of Amos ("Two years before the earthquake"), which was about 65 years before the Samaritan exile, and claim that Isaiah here is quoting or alluding to this well-known prophecy, and is not establishing a new count.
My question:
From a biblical-contextual perspective, are there real indications that this is a quote/allusion to the prophecy of Amos, or is it primarily an interpretation intended to resolve the chronological problem? In other words, does Chazal's solution stem from the text itself or is it a result of the need to protect the reliability of the prophecy?
Thank you very much.