Um. Who is this “all”? Did Shakespeare’s company have a large chorus of people who could just be on-lookers?
I mean – first there is the question of what this call of treason is referring to. Is it Hamlet who is committing treason by killing the king? That seems the standard definition. But, there is also the treason that the king himself has committed against his office. In that case, these calls of treason became a sort of cheerleading of Hamlet’s vengeance.
But practically – who is part of this “All”? Laertes is dying and unlikely to shout. Horatio is team Hamlet but it’s hard to imagine him shouting “Treason!” Gertrude is dead and cannot call. Hamlet probably doesn’t say it himself. Claudius might. But he’s got other things to do, like managing his injury. Which, of the people onstage – leaves, essentially Osric. Who is not an all.
Basically we have six people definitely onstage and another person with some troops about to come on.
Did the King’s Men bring back the actors playing Polonius and Ophelia and Rosencrantz and Guildenstern to come be a crowd and shout “treason!”
From what I remember, Shakespeare’s company was made up of about 15 people – which means this “all” here is probably pretty small.