No one knows how many members the Arakan Rohingya Salvation Army has, no one knows who they are, they don’t wear uniforms. They just gave the military a rationale for targeting ANY individual Rohingya as a militant, and no one can disprove them. They can now raze whole villages under the pretext of trying to target the insurgents’ support network.
You can say “they were targeting individuals and razing villages anyway”, but their pretext for doing so was easily refuted…now it isn’t. Ata Ullah just absolved the military of blame for any atrocities they want to commit.