Now we know a sequel to DMC serie would be very hard considering how badly the story has been neglected every since DMC 1. After DMC 1 , DMC 2s story was like a filler episode from a anime. A filler means a episode not related to the main story.
Now we all want to know Vergils story. And Dante´s story when they were teen.
Hideki Kamiya who has said that if he got chance to make another DMC game "i would do what all fans want".
In other words: If you want to see Dante and Vergils childhood and what happened to them after the murder of their murder - then the possibility of that is possible. However, it does´t seem likely Capcom will hire PG considering that PG consists of former Capcom staff.
With DMC creator i believe the story of a DMC prequel could be good. I hope for better though
When it comes to gameplay it would require more work. For example you will need to make new character designs of Dante and Vergil as kid, and makes their moves fixed etc.