Yes, it is correct. Favored Souls have a split casting stat. Spells/day and max level is set by their Charisma, the DC of their spells is set by their Wisdom.
Spirit Shamans also have a similar split, though in their case it's the other way around.
A phrase used to describe classes that need high numbers in more than one stat for optimal performance. . . like for example, 3rd ed Psionicists, or a Favored Soul who needs Charisma to cast spells and Wisdom to power them.
Honestly...I don't know. We've houseruled them to be Divine Sorcerers. Charisma for Spells, Charisma for DC...no reason to gimp a class by splitting the attributes.