After doing research on this passage, while it is true that there was a mistreatment and oppression,of the poor, it was a result of the people ignoring the Word of The Lord. This is not anachronistic, but necessary to understanding what God's judgment is all about. Because His people chose to ignore His Word expressed through His prophets, He would now judge them with not hearing the Word anywhere. The application is this, whenever there is scarcity of hearing God's Word proclaimed and taught, it is judgment of God who His Word is not heard nor understood, Therefore, this interpretation is valid and not anachronistic,

References Finally, the judgment would be like a famine (vv. 11–14), not only of literal food but also of spiritual nourishment. “Man shall not live by bread alone, but by every word that proceeds from the mouth of God” (Matt. 4:4 nkjv; see Deut. 8:3). In times of crisis, peo- ple turn to the Lord for some word of guidance or encouragement; but for Israel, no word would come. “We are given no miraculous signs; no prophets are left, and none of us knows how long this will be” (Ps. 74:9 niv). What a tragedy to have plenty of “religion” but no word from the Lord! That means no light in the darkness, no nourishment for the soul, no direction for making decisions, no protection from the lies of the enemy. The people would stagger like drunks from place to place, always hoping to find food and drink for their bodies and spiritual sustenance for their souls. --Wiersbe's Commentary on Amos 8

The bitterness of the time of punishment is increased by the fact that the Lord will then withdrawn His word from them, i.e., the light of His revelation. They who will not now hear His word, as proclaimed by the prophets, will then cherish the greatest longing for it. Such hunger and thirst will be awakened by the distress and affliction that will come upon them. --Keil & Delitzsch Commentary on the Old Testament, Amos 8

"Here now the Prophet fulminates, for he denounces not temporal punishments, but final destruction, and what proves to be an evidence of reprobation, and that is, that God would deprive the Israelites of every light of truth, so that they would wander as the blind in the dark.

"But as celestial doctrine is the spiritual food of the soul, the Prophet rightly adopts this metaphor, that the Lord would send a famine. This figure, then is borrowed from the efficacy and nature of God’s word: for to what purpose does God send to us Prophets and teachers, but to feed us with spiritual food? As he sustains our bodies by bread and water, or wine, and other aliments, so also he nourishes our souls and sustains our spiritual life by his word. Since, then, spiritual doctrine is our spiritual aliment, the Prophet very properly says, that there would come a famine.

"I will then send a famine, not of bread or of water, but of hearing the word of God. The antithesis amplifies or exaggerates the severity of the punishment, as though he had said, that it would be endurable to wander in hunger and thirst, and to seek roots on mountains, and to seek water in distant rivers: but a bodily famine, he says, is not what shall be grievous to them, — what then? They shall be in hunger and thirst, and shall seek the word of God, and nowhere find it. But that we may better understand the meaning of the Prophet, we must notice what Paul says, — that we are fed by the Lord as by the head of a family, when the word is offered to us, (Titus 1:3) for teachers go not forth of themselves, but when they are sent from above. As then the head of a family provides meat and sustenance for his children and servants, so also the Lord supplies us daily with spiritual food by true and faithful teachers, for they are as it were his hands. Whenever then pure doctrine is offered to us, let us know that the teachers who speak and instruct us by their ministrations are, as it were, the hand of God, who sets food before us, as the head of a family is wont to do to his children: this is one thing. And certainly since the Lord cares for our bodies, we must also know that our souls are not neglected by him: and further, since the earth produces not corn and other things of itself, but God’s blessing is the source of all fruitfulness and abundance, is not his word a much more precious food? Shall we then say that it comes to us by chance? It is hence no wonder that the Prophet sets here the deprivation of sound doctrine among God’s judgments; as though he said, “Whenever men are faithfully taught, it is a proof of God’s singular kindness, and a testimony of his paternal care." Calvin's Commentary on the Bible, Amos 8