An explanation for the two near-simultaneous DLvdE releases from Jonathan Nott:
1) The Tudor release was a long-planned recording, part of his complete cycle on that label. It's the "official" Nott DLvdE.
2) The Sony release was a Sony/Kaufmann project designed to showcase Kaufmann's tour-de-force vocal casting. Daniele Gatti was booked to conduct. When Gatti had to withdraw due to a shoulder injury, Nott was available and brought in as a last-minute substitute, not only for the recording but for the several surrounding concerts presented in Vienna, Paris, etc..
James