In the article I cited with Sean Carroll, I predicted that the Joyce- Shaposhnikov mechanism could create a helical magnetic field in the early universe, which would be available for incorporation into the intracluster gas in clusters. Gauss, smaller than our upper limit. The observed scale is larger than we would predict, however, but not hugely so. Recall that the J-S mechanism produces a helical field, a fact that is crucial in attaining astronomically interesting scales today. There is evidence from other clusters that the field is helical in shape.
More work is needed.
The prospect is exciting because it constrains parameters of the early universe - and there are few such constraints.