I think first what we have to deal with is;
did Sparda do the same as Dante? how did he exactly "seal Mundus' power" I mean Dante just seemed to kick him out of the human world and shut the door behind him, is that what Sparda did? or did Sparda defeat Mundus and perform some sort of spell on him? or was it the spell gate that sealed his power?
It took Mundus 20 years after he woke up (in DMC3) to get his powers back after whatever happened between him and Sparda so it is really a question of whether he is strong, ready and waiting for the gate to open again or if he is a evil orange puddle on the floor gradually restoring his power.
^now I know that isnt right, I think I need to play DMC1 again..
Anyway I dont think he will..its too soon after DMC1