I'm afraid that mikoto and amarant never even begin to suggest Terra was blown up. 🙁 Destroyed means rendered unusable, not blown apart entirely.
The fact is that the Bal Bal cutscene, Kuja's words, and even the quote you love taking out of context prove that it was nothing but surface damage. Even worse, Terra is seen plain as day merging with Gaia at the end, completely intact. I'm afraid that on screen proof >>>>>>> you trying to change the meaning of a single NPC quote because you love Kuja so.
Kuja never blew up a planet and he gets stomped into the curb by any form of Exdeath.