Moses was buried by God.
Deuteronomy 34:5-6
So Moses the servant of the LORD died there in the land of Moab, according to the word of the LORD.
And He buried him in the valley in the land of Moab, opposite Beth-peor; but no man knows his burial place to this day.
Elijah was not buried.
2 Kings 2:11
Then it happened, as they continued on and talked, that suddenly a chariot of fire appeared with horses of fire, and separated the two of them; and Elijah went up by a whirlwind into heaven.
Moses wrote those words, before he left the camp. You think someone else wrote those words, about Moses.
What actually happened is an unknown, until the NT. Then we see that Satan, in death, did not get the body of Moses. Who was lying, Moses in writing his own epitaph, or Jude under the inspiration of the Holy Spirit? Moses wanted them to accept he was dead. Moses may or may not have known what would happen. In fact he told them not to go look for a body, that God had it all handled. You accept God came down, and personally buried the body, no? Well Adam's dead flesh could not enter Paradise, so that means that Elijah was not in Adam's dead corruptible flesh, but had already been translated into God's permanent incorruptible physical body.
God could have already changed Moses like He did Enoch. But we will never know. Moses disobeyed God, so he could not enter the promised land, where he could have lived another 40 years as their leader. He could have entered heaven in a fiery chariot. But Moses had told them many times that disobedience leads to death. So Moses left in disgrace, because he disobeyed God. He made sure they knew one thing; that he was dead, as there was no victorious leaving for him, as he had disobeyed God, and left the camp in punishment.
In Revelation there are 4 witnesses. 2 from the OT, the olive trees, and 2 from the NT, the candlesticks. Those from the OT already served God in the OT. The 2 candlesticks will serve God during those 42 months given to Satan. The 4 witnesses are symbolized here:
"And before the throne there was a sea of glass like unto crystal: and in the midst of the throne, and round about the throne, were four beasts full of eyes before and behind. And the first beast was like a lion, and the second beast like a calf, and the third beast had a face as a man, and the fourth beast was like a flying eagle. And the four beasts had each of them six wings about him; and they were full of eyes within: and they rest not day and night, saying, Holy, holy, holy, Lord God Almighty, which was, and is, and is to come. And when those beasts give glory and honour and thanks to him that sat on the throne, who liveth for ever and ever,"
Having eyes to see everything that goes on is symbolic of a witness redeemed out of Adam's dead corruptible flesh. Just like the 24 elders redeemed from Adam's dead corruptible flesh, 12 from the OT, and 12 from the NT. In chapter 11, John gives a more relatable view of the 4 witnesses.