In Theravada the focus on the dead body is from the perspective of the dissolution phase of impermanence. This meditation is an antidote to sensual desire:
“And further, as if he were to see a corpse cast away in a charnel ground—one day, two days, three days dead—bloated, livid, & festering, he applies it to this very body, ‘This body, too: Such is its nature, such is its future, such its unavoidable fate."–MN 10
Also reliance on rites and rituals is a fetter abandoned at stream entry.
“He attends appropriately, This is stress… This is the origination of stress… This is the cessation of stress… This is the way leading to the cessation of stress. As he attends appropriately in this way, three fetters are abandoned in him: self-identity view, doubt, and grasping at habits & practices.”—MN 2