Sadr always proposes to disband the Mahdi Army upon orders from the Najaf Hawza whenever there is some sort of controversy - he also did this back in 2004 and after Karbala in 2006. He knows that the Hawza will never intervene so directly into politics and publicly order said disbandment specifically for the Mahdi Army alone. Most likely is that the Hawza refused to acknowledge the query at all.

The Mahdi Army is not going to disband any more than the Badr Brigade "disbanded" by rebadging itself in Interior Ministry uniforms and calling itself the Badr "Organization."