"We definitely appreciate that the community has a lot of interest in seeing the Diablo series continue, and we certainly share that desire." - Blizz Person
Plus the orchestra in Czech republic that recorded the sound for D2 LoD admitted to recording newer Diablo-sounding music for Blizzard not too long ago. Could be for something else but seeing as it's the same people that recorded for D2.. they know the music style and to them sounded like Diablo.

gogo.