In addition to Nagano's championing of the new, there is the deep respect for the past.  After Günter Wand's death in February 2002, Nagano conducted the memorial concert given by the Deutsches Symphonie Orchester Berlin.  He performed the original version of the Third Symphony, which Wand had never done.  Why?

I had endless discussions about this work with Wand.   In our last debate, which lasted for an entire evening, he ended the evening by saying he wasn't sure himself. When we record the Third Symphony this year it will be the original version, which somehow exposes once again the brilliance, the genius, the revolutionary side of Bruckner, not only because of the freedom in which he expresses his choice of harmonic development (at times so radical that it simply breaks the limits of tonality) but also how far he expanded the structural thinking of the time.

Wand and I, over eight years, went through the entire Bruckner canon more than once, twice, three times and Schubert canon.  He systematically went through all the [different Bruckner] versions and chose to perform those that he felt were most consistent with Bruckner's aesthetic. He didn't modify his chosen edition at all.  But he would always be open to discussion about them.