Regarding Gst Returns

Dear all,
One of my clients Gstr 3B is pending due to a huge amount of refund for which appeal is to be filed. So they have not filed their Gstr 3B since 8 months.
Now they a receiving notice for suo moto cancellation.
My query is
As per Sec. 39, it says that a commissioner can extend the time limit for filing returns.
So on the basis of said rule,can he request to extend the time limit for filing his return by explaining him the total scenario, and his registration also won't be cancelled.
Please provide ur valuable suggestions