From the river to the sea has existed a lot longer than Hamas has in in power. A conservative government can’t “claim” a half century old chant.
Australia’s national animal is a kangaroo. If I draw a kangaroo on the canvas, does it mean I support the dictatorship of Australia? No, of course not. Because Australia doesn’t get to own the idea of kangaroos. And Hamas doesn’t get to own this chant. This chant is a lot less tied to the views of a conservative government than the German flag it’s drawn on.