I'm so glad you mentioned this.
Yes you could.
You also notice that near the middle of the bus body, right above the wheel wells, that sheet of outer skin had ribs pressed right into it? That's the profile you mention.
After reskining the sides of my bus, and doing a tin roofing job, I started thinking about contraction and expansion. Roofing tin has ribs pressed into it every 6 inches or less. I always thought this was just for strength, and rigidity.
Well it turns out both the roofing tin and the sides on my blue bird bus were both ribbed to give the steel somewhere to expand to without oil canning just like you mentioned.
So, for those of us who are reskining the sides after window removal, having a metal shop press ribs that match the rub rails into the new sheets would reduce the amount the new steel tries to buckle / wrinkle, and eliminates the need for rub rails.
One more advantage, is the fact that rub rails collect crap behind them, cause rust to start. With the new one piece panels with rub rails pressed into it, all seams will over lap the proper direction, keeping the water and road grime out.
The next bus I build, I will be reskining the entire sides, and implementing the one piece panels with built in rub rails.
Maybe I will even used polished stainless steel for a chrome look.
Slowly this site is evolving the skoolie conversions. Better idea's, Better methods, Better materials.
Just look at how many of us are doing roof raises now.