You can still use the product on Vatsim and maintain a level of real world operational accuracy. Most Vatsim controllers will never assign 10C/28C (let alone 10R/28L when it opens this week), and realize everyone is using various "out-dated" sceneries, therefore will strictly use 28R/22L, 10L/9R for departures and 27L/R, 28R, 10L, 9L/R for arrivals, which are included in the FSDT scenery and used today in normal ops.
Nonetheless, definitely looking forward to a KORD update when released!