I'm going VNY-LAS. DUATS auto routing came up with a route that ends
at OASYS on V394. Trick is, OASYS is not an IAF for any approach into
LAS as far as I can tell. What should I do if I lose comm?

Comm loss is covered in the AIM Chapter 6 Section 4.
Please see the link below

http://www.faa.gov/atpubs/aim/Chap6/aim0604.html#6-4-2