If I understand correctly, you describe the habit or behavior of the majority of the uncircumcised. In fact, leaving out those who choose to keep the foreskin retracted, the uncircumcised usually have the glans continually covered by the skin (when penis is flaccid). This normally, except in cases of a tight foreskin regardless, does not cause problems or who knows what effects. Among other things, only a minority have a short foreskin or always leave it retracted.
The speech is logically different with an erect penis (again excluding, I emphasize, those suffering from phimosis). In most men, the foreskin retracts automatically with an erection. Other guys foreskin's retracts partially or only manually but, once lowered, it remains in that position. So it is really difficult to have the glans completely covered (with an erect penis). Only a small number of people, in the absence of pathologies or medical problems, correspond to this anatomical variant.
I conclude, hoping not to have bored anyone or gone off topic, stating that in my opinion it involves more changes an uncovered glans with the foreskin always retracted than vice versa.