The five-minute piano solo is dedicated "to the journalists of Gaza," according to D'Netto.
The MSO said it does not condone the expressing of political opinions onstage and apologised for the comments.
Comments of that sort would be clearly unprofessional in the context of a more "ordinary" job, but I suppose a musician might feel that his performance is not just work for pay but also a form of self-expression. Clearly the orchestra disagrees, although perhaps they would have tolerated something more anodyne like "world peace".