There is a gray area on the effect of White rot fungi on Humic substances. Some claim that they have observed the formation of humics in the fungal cultures, some have reported the complete opposite; degradation of humics.
I attached an article from the same authors of the article that you attached. Its a review. there they mentioned the dilemma that i mentioned in the question, also they referred to some articles that are talking about humification or formation of humics by WRF.