This story is unusual because the personal name of one of the characters is mentioned.
From Haydock’s Commentary:
Divers interpreters have looked upon this as a true history; but what is said of the rich man seeing Lazarus, of his tongue, of his finger, cannot be literal: souls having no such parts. (Witham) — In this parable, which St. Ambrose takes to be a real fact, we have the name of the poor mendicant; but our Lord suppresses the name of the rich man, to signify that his name is blotted out of the book of life: besides, the rich man tells Abraham, that he has five brothers, who were probably still living; wherefore, to save their honour, our Lord named not their reprobated brother. (
source)
From
A Commentary on New Testament published in 1942 by the Catholic Biblical Association:
A few of the Fathers thought that our Lord referred to a strictly historical fact here, but the common opinion holds that this is a true parable, i.e., an imaginary but entirely plausible story to point a moral lesson. (
source)
Either way, I don’t see how this story supports “soul sleep” since at least two of the three souls mentioned is conscious and communicating with each other.