Sometimes the term CROSS in the bible refers to the literal gallows they used to "gibbet" a person, hanging by hands, not noose. At other times it means THE DOCTRINE OF THE CROSS, and in those cases, burial and resurrection are also implied without doubt.
Preaching of the cross is doctrine of the cross. (1 Cr 1:18 For the preaching of the cross is to them that perish foolishness; but unto us which are saved it is the power of God.) That doctrine teaches His sacrifice removed our sins. The epistles teach that resurrection proved His sacrifice was effective! So in those instances where preaching of the cross is mentioned in order for salvation, it is understood that burial and resurrection are noted. But not simply observational burial and physical resurrection in and of themselves, as though to say Paul ONLY MEANT someone's death. The resurrection physically occurred,
but for the purpose of confirming that the death was efficacious and that Jesus conquered death.
It's like
Heb 2:14-15. Jesus partook of flesh and blood to be able to die so He could destroy the devil who had the power of death, and deliver those who were in bondage. You could use the reference to Christ's death and isolate it from the resurrection just as people isolate the cross from the burial and resurrection. But you would miss the fact that the MANNER in which Christ's death destroyed the devil was due to Christ's conquest of that death in His resurrection!
The preaching of the cross means that if we believe in Him we shall be saved from sin. But just considering the outward activities of His heart that stopped beating due to DEATH would not allow for that in Paul's reference to the preaching of the cross. This proves that Paul often encapsulated entire teachings with one word, just as CROSS, for otherwise what would the preaching of a heart ceasing to beat causing death mean to anyone if that was all that was preached to heathens who never heard anything about the concept of atonement and vicarious sacrifice? Imagine if CROSS only meant DEATH in the strictest sense, and we preached THE CROSS in that manner to heathens alone. Nothing is said about WHY He had to die, since the term DEATH alone does not strictly concern itself with WHY, but means cessation of life.
"A man named Jesus died for you!" Period.
We know that is not what is meant by the preaching of the cross any more than the "cross" likewise not implying burial and resurrection.