Using rearsets with low bars ( whether it be clubmans,superbike,moto gp...etc) does not take weight off of your wrists.
When your feet are under you (e.g.- stock pegs) you can hold your torso weight up with a mixture of balance and stomach/back muscles. When you kick your feet backwards ( rearsets) you can no longer balance and it THEN forces all of your weight to hit your wrists.
Sit on a bike with stock pegs. Put your feet on the pegs. Put your hands in your lap. What happens? Nothing. You're balanced and you can sit upright all day without needing your hands.
Now,sit on a bike with rearsets. Put your feet on the pegs. What happens? If you don't put your hands out if front of you somewhere you're gonna fall forward.
This is why I went back to stock pegs with clubmans after trying rearsets. Less pressure on my wrists.
Granted,the bars are low, so you DO have to lean forward to reach them . How far you have to reach is dependent on your arm length,seat height... so naturally you will be putting more pressure on the bars,but not nearly as much as you would with rearsets.
Long story short,if you got rearsets,you're counting on your bars to hold you up. With stock pegs you just start out more balanced to start with.