The bags which were placed along the top of the spillway were reportedly sealed together with concrete, but those were fulfilling a different purpose, diverting water away from the damaged section while the threat of overtopping remained. The ones on the embankment are only providing mass; I read a report earlier where an engineer said they would need to be removed before a permanent repair was made (sorry, can’t find it again). There would be no point in repairing the spillway over the bags in that case.