Its a long story but it is semi-canon. Or something. Depends how you wanna look at it. Since 4:SE and 5 ignore it, i dont think it is, but since it hasnt been declared one way or the other, its really up to you.
The writer took aspects of that novel. The neon DMC logo that Dante gave to Nero was shown in 5.
The DMC1 Novel goes against what happens in DMC3, but that's canon now. In the DMC1 Novel there was no Rebellion, Dante used the Force Edge.
The wiki lists it as semi-canon.
"Any events that is able to fit within the story of the video-game, however, is canon."
@saxophones: DMC5 also ignored a buncha stuff from yhe novel as well, like Nero dreaming of Vergil and the entire scene where Vergil converses with him during his temporary death.
DMC1 novel ismt totally canon, it cant be. The way i look at it is that DMC5/BtN took a lot of effort clear up what events occured within thw continuity of the series and reincorporated certain elements from external material and whatever wasnt mentioned isnt canon at all. Thats just me.