I did the WE but I was CC touring so I did not need to worry about campsite issues.
That said, you may want to be cautious and hang your food if you're wild camping from when you first head west from Pueblo till you get to Delores by the Utah border. I don't think you'll need to worry about it again until the Carson Pass area. I say that just from looking at bear range maps. I do not recall seeing any signage about being "Bear Aware" at anyplace along the route. Even in someplace like Sargent (below Monarch Pass) which is very rural and and wooded, or around Telluride, I do not recall seeing any bear signs.
Actually the only time on that route I worried about the .0000001% chance of an ugly wildlife encounter was when I was on the alternate route (722) between Middlegate Station and Austin. Sixty something miles and I wasn't passed by a car the entire time. As I climbed up the passes on that road the surrounding rocks looked like perfect mountain lion territory and I assumed if one saw me I would look like slow & easy pickings!
I think you'll love the route, I certainly did. A detour to Zion NP is certainly worthwhile but a pretty big detour. Make sure you at least go the extra 10 miles to include Bryce Canyon.
Pete