Your guess is as good as mine. :/
I still have a hard time with Vergil's logic of Eva abandoning him.
The attack came out of the blue. Dante and Eva were in the house. It seems, he already hid under the bed when she came and put him in the closet. Both didn''t know where Vergil was at the moment. She rushed of to search for him and was quickly killed. (So now Dante could be angry at Vergil for being the reason Eva got killed? ^^)
Maybe Vergil was outside playing? Demons came and chased him away? He got lost during his escape from them?
We have no idea. On the other hand, Vergil has no idea either. He can't know that Eva hid Dante, he wasn't there. Why is he sure, she didn't come for him?
Next is his thought of them being switched. Would that really make such a difference?
In the original story, where he was captured and turned into Nelo for sure. But with DMC3? They both came out of it alive and spend the next years on the run.
The prequel novel states Vergil didn't hide his identity, so Mundus found him sooner and sent demons, Vergil defeated. Later he did the same with Tony, and with them destroyed was sure, it's Dante.
Where is the big difference why he envys his brother?
The attack scene is quite short and doesn't tell much. Isn't it a bit surprising they didn't find Dante in the closet? The house was set on fire as well. Did he just stay in there until the demons left?
So regarding V... When he reaches his old home with Nero, he starts to tell him about it. He says he just remembered, but I'm not sure if that's not just an act.
He says, the town was attacked before. "In fact I was playing right here". And I assume, he really means, he was playing there when the demons came. When he points to the house you can see, how far away it was. No wonder Eva had no idea were he was and no chance of finding him.
Makes his claim even more strange of being abandoned.