Yes, it is possible perform a AUTOGEN function in simulate mode. One just has to add the following DD statement to their batch JCL:
//EN$AUSIM DD SYSOUT=*
For more information on EN$AUSIM please go to the V18 Endevor Documentation WIKI
One important note on the use of //EN$AUSIM DD statement - it will put all actions in a simulate mode not just the action using AUTOGEN.