I just attended a performance of Macbeth that ended on a much more ambivalent note than Shakespeare's original text. Instead of Malcolm and his posse picking up the shambles and Malcolm motivating his men to look into a brighter future, it actually ended with Macduff crowning Malcolm, surrounded and cheered on by the witches who start to recitate, together with Malcolm even, the "fair is foul" rhyme.
This paints a lot darker prospect of the future, if we understand it as Malcolm ultimately becoming (if not already being) a playball for the witches' schemes as well. It then reminded me of the Justin Kurzel adaptation from 2015, which also had a more ambiguous ending that left me wondering a little. But even more so, I rechecked the 1971 Polanski adaptation and it also ended with Donalbain visiting the witches, possibly implying he'll end up falling for their schemes as well.
Now my experience with Macbeth largely comes from cinematic adaptations, but in retrospect on these and reinforced by the performance I just attended, I can't help but notice a trend of having the play end on a much more ambiguous or even pessimistic note than the original text seems to suggest. But maybe it is also just me failing to read the subtext in the play's ending and it already contains more ambivalent undertones that I just missed in the dialogue. These endings do fit not too badly to the rest of the play's overall tone, especially if we take it as a general parable for the corrupting nature of power.
So to condense these ramblings into a hopefully not too broad question, I'd like to know more about the evolution of these interpretations. Are these pessimistic tendencies already present in the original play? If not, when did these more ambiguous intepretations of the ending emerge? Is this a generally exhibited approach to the play nowadays, maybe as a natural extension of its themes and is this trend maybe pointing to a larger difference in how the characters' motivations are seen? Basically, has the understanding of the larger-scale themes of the play maybe changed throughout history?