Yes, it can be automated to republish out of date reps. I believe the setting is in your wvs.properties (windchill/codebase)...not sure of the exact changes needed. Read: http://yourserver/Windchill/properties.html#WindchillVisualizationServiceProperties. One thing to note....this will create a lot of extra publishing, when we had this turned on our two publishing machines were working 24/7 and the only time they would catch up would be on the weekends. I also warn about turning this function on as you lose eyes on drawings. What I mean by that is once you check something in, an engineer should check the published drawing to make sure that everything looks correct. We have run into instances where it looked correct once published after initial checkin, but after a while due to a automatic republish the drawing lost dimensional references and a supplier made parts that were not correct. This didn't sit well with our quality dept.....so we stopped auto re-publish. The engineers are in charge of checking drawings and republishing were used assys and drawings. This adds a little time, but ensures that every rep in your system is perfect (per engineering and company standards).
Greg