Greetings Matt:
Good question! After looking through a couple papers at the 2007 Oak Wilt Symposium held in Texas, it does not appear that the fungus is transmitted outside the primary phases of transmission: vector-borne via insects (e.g., Nitidulidae) and xylem-limited disease spread via live root grafts of infected trees (MacDonald et al., 2009). This does not mean, of course, that the young oak trees as they grow and age over time are immune to oak wilt; rather, it simply means that oak wilt is not sitting dormant in the soil waiting to attack newly planted or germinated oak seedlings.
Here is an identical question posted on the University of Minnesota Extension Forestry Web site and the author(s) response to that question.
Will newly replanted oaks be more likely to get oak wilt?
In general, replanting of oaks in an old oak wilt disease center does not result in disease occurrence in the replanted trees. Root grafts are not thought to form with the dead, diseased oaks. Thus, it is only through insect spread from active oak wilt centers in the vicinity that disease would occur in replanted oaks. Oak trees that are healthy are not susceptible to oak wilt in an infected area. Soil, chipped and debarked wood will not harbor the oak wilt fungus.