While I don't agree with the term "soul sleep", I do agree that what makes us "us" exists in an unconscious state until the resurrection.
I'll address the use of the term sleep in the bible for starters. The author implies that the verses he mentioned is the extent of the sleep=death in scripture, but he leaves out several verses:
Job 14:12 So man lieth down, and riseth not: till the heavens be no more, they shall not awake, nor be raised out of their sleep.
This seems to be a definitive statement.
Daniel 12:2 corroberates this view:
Dan 12:2 And many of them that sleep in the dust of the earth shall awake, some to everlasting life, and some to shame and everlasting contempt.
Death is compared to sleep by the Lord:
Jer 51:39 In their heat I will make their feasts, and I will make them drunken, that they may rejoice, and sleep a perpetual sleep, and not wake, saith the LORD.
And again:
Jer 51:57 And I will make drunk her princes, and her wise men, her captains, and her rulers, and her mighty men: and they shall sleep a perpetual sleep, and not wake, saith the King, whose name is the LORD of hosts.
Speaking of Moses death, God says again:
Deu 31:16 And the LORD said unto Moses, Behold, thou shalt sleep with thy fathers...
God once again says:
2Sa 7:12 And when thy days be fulfilled, and thou shalt sleep with thy fathers, I will set up thy seed after thee, which shall proceed out of thy bowels, and I will establish his kingdom.
In fact, the term "slept with the fathers" is used to denote death in the old testament close to 40 times. Again:
Psa 13:3 Consider and hear me, O LORD my God: lighten mine eyes, lest I sleep the sleep of death;
Jesus tries to teach people that death is comparable to sleep in the story of the dead maiden in three of the gospels:
Mat 9:24 He said unto them, Give place: for the maid is not dead, but sleepeth. And they laughed him to scorn.
Mar 5:39 And when he was come in, he saith unto them, Why make ye this ado, and weep? the damsel is not dead, but sleepeth.
Luk 8:52 And all wept, and bewailed her: but he said, Weep not; she is not dead, but sleepeth.
And John in the tale of Lazarus:
Joh 11:11 These things said he: and after that he saith unto them, Our friend Lazarus sleepeth; but I go, that I may awake him out of sleep.
The resurrection of the saints upon the death of Christ:
Mat 27:52 And the graves were opened; and many bodies of the saints which slept arose,
Stephen is stoned, his death is called sleep:
Act 7:60 And he kneeled down, and cried with a loud voice, Lord, lay not this sin to their charge. And when he had said this, he fell asleep.
Again in Acts, King David is described as sleeping:
Act 13:36 For David, after he had served his own generation by the will of God, fell on sleep, and was laid unto his fathers, and saw corruption:
Paul describes death as sleep 5 times in 1 corinthians in describing the resurrection :
1Co 11:30 For this cause many are weak and sickly among you, and many sleep.
1Co 15:6 After that, he was seen of above five hundred brethren at once; of whom the greater part remain unto this present, but some are fallen asleep.
1Co 15:18 Then they also which are fallen asleep in Christ are perished.
1Co 15:20 But now is Christ risen from the dead, and become the firstfruits of them that slept.
1Co 15:51 Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed,
And again in Ephesians:
Eph 5:14 Wherefore he saith, Awake thou that sleepest, and arise from the dead, and Christ shall give thee light.
1Th 4:13 But I would not have you to be ignorant, brethren, concerning them which are asleep, that ye sorrow not, even as others which have no hope.
And:
1Th 4:14 For if we believe that Jesus died and rose again, even so them also which sleep in Jesus will God bring with him.
1Th 4:15 For this we say unto you by the word of the Lord, that we which are alive and remain unto the coming of the Lord shall not prevent them which are asleep.
Peter also compares death to sleep:
2Pe 3:4 And saying, Where is the promise of his coming? for since the fathers fell asleep, all things continue as they were from the beginning of the creation.
These are just the 60 or 70 something verses I found that used the terms "sleep", "slept" or "asleep" for death. There are many others that denote a state of consciousness like sleep but doesn't use the words.
In short, instead of "sleep" being used in isolated verses instead it's clearly and consistently used to describe the state of death.
What's astounding is that the both the old testament and new testament agree that death is sleep. God himself, who presumably would know, clearly likens death to sleep. Jesus Christ likens death to sleep. Mark, John, Luke, Paul, and Peter all agree...death is like sleeping.
Now with all this scripture detailing that death is like sleep, I don't feel comfortable blithely dismissing it as a euphemism used by God in heaven, God incarnate, Peter, Paul, Mark, Luke, and John.