Seems odd to have an erosion problem on gas turbines.
The only reason I can imagine for blade erosion on a combustion turbine is condensation in the gas.
But at the temperatures that gas turbines operate I can’t see how there would be any condensation.
The remote possibility of ash isn’t worth thinking about.
Combustion turbines suck in lots of outside air with the natural gas. Any particles in that air cause problems like river water eroding rock over time.