Is Uncle Sam really dead at the end of Pinter's The Homecoming? There are jokes made about his state and Joey even says "He's not dead" to which Lenny responds with another joke. I think, 'collapse' of Uncle Sam would be the better expression to use.
Sam's collapse is used both as an important informative device in the play as well as a comical (sardonically comic of course) event in the play. It marks a climactic movement in the play. What Uncle Sam discloses is the fact that MacGregor had a sexual intercourse with Max's wife Jessie as he drove the cab. This is the repressed secret that leads to Sam's anxiety-breakdown at the moment of the articulation.
The truth that is revealed in the process is crucial because it once again breaks down the mother-whore binary. Jessica is the absent mother in the play and this jettisonning of the mother-whore binary in her case thus anticipates the final image of the play where Ruth steps onto her shoes and becomes the master of the house, a curious combination of the mother and the whore.