I am unwilling to credit Biblical prophecy as true in every jot and tittle conveyed by modern translation. Moreover, a close reading of Maccabees might distinguish known as meaning known to the people, not the secret knowledge of those who may have moved the Ark from Mt. Nebo to a new location to protect it.
That’s why it’s good to look at a variety of translations and even the Greek or Hebrew if you can and what other reputable scholars and commentators have said about it. The early Church Fathers, for example, simply took the prophecy at face value.
Moreover, a close reading of Maccabees might distinguish known as meaning known to the people, not the secret knowledge of those who may have moved the Ark from Mt. Nebo to a new location to protect it.
That’s plausible, of course, except the text doesn’t support that there will a persons or persons finding it and then keeping it secret from everyone else, but that it’s revelation will be highly visible and undeniable event.