If that were true, Paul would be a contradictory fool! He is saying no less here than what he has said elsewhere. Paul says here, the same thing he does in 1Co 15. He longs to be free from his mortal body of death, because he knows that it will not be the end of him, for he will be a spiritual body in the Kingdom of Heaven after he breathes his last on this earth.
2Co 5:6 Therefore
we are always confident, knowing that, whilst we are at home in the body, we are absent from the Lord:
2Co 5:7 (For we walk by faith, not by sight
2Co 5:8 We are confident,
I say, and willing rather
to be absent from the body, and to be present with the Lord.
Php 1:20 According to my earnest expectation and
my hope, that in nothing I shall be ashamed, but
that with all boldness, as always,
so now also
Christ shall be magnified in my body, whether it be by life, or by death.
Php 1:21 ¶ For to me
to live is Christ, and to die is gain.
Php 1:22 But if I live in the flesh, this
is the fruit of my labour: yet what I shall choose I wot not.
Php 1:23 For
I am in a strait betwixt two, having a desire to depart, and to be with Christ; which is far better:
Php 1:24 Nevertheless
to abide in the flesh is more needful for you.
Christ too, knowing in physical death He would be a spiritual body, with the Father in heaven, promised the thief that on that day he too would be with Christ in heaven (Paradise).
Lu 23:43 And Jesus said unto him, Verily I say unto thee,
To day shalt thou be with me in paradise.
Lu 23:46 And when Jesus had cried with a loud voice, he said,
Father, into thy hands I commend my spirit: and having said thus, he gave up the ghost.
So too, Stephen, who was martyred, knew in death his spirit would go to be with the Lord in heaven.
Ac 7:59 And they stoned Stephen,
calling upon God, and saying, Lord Jesus, receive my spirit.