I think the upgrades should make a difference, they do in the real world why not in the virtual one. Whether in the simulator or in the real world Strava leaderboards are affected by much more than just the athlete’s performance - wind, riding companions, bike, wheels, tire pressure, rain/dry, the clothing and helmet chosen etc. all have significant effects. I wouldn’t take those standings too seriously either in the real world or the simulated one, and I say that not to pooh-pooh it – it just needs to be taken in perspective. For the purposes of tracking your training efforts, whether in the real world or the sim it is not the time/speed or leaderboard standing that counts, it’s your watts, watts/kg, and power/time curve that are most interesting. The power/time curve tells all you need to know about someone’s effort, it’s the first thing I look at when I take a look at a friend’s ride to see what sort of effort they put down. This curve is entirely unaffected by the equipment used.
Also I think there’s a business model to be exploited surrounding ‘virtual’ equipment just like in other online gaming. You could earn these things through achievements or pay for them through cash. And it’s all good, it’s just a game. Heck I bet there would be lots of people who would enjoy it the other way around, say to be able to choose to ride an MTB with higher wind and rolling resistance and have your rider animation be on an MTB, require higher watts, then go hunting to humiliate people with their upgraded aero bikes and aero helmets within the sim. Anyone riding the upgrades had better be the fastest on the course or else it would be embarrassing, which is all part of the motivation/fun.