Depending on the thermal conductivity of the carbon fiber used, it could actually make for a barrel that gets hotter internally, similar to wrapping insulation around it. Which is usually not good for barrel life.
So was this analysis you mention based on proper bore scope analysis and comparison over many barrels of each kind? or " it just happened to shoot well longer ", which could stem from other factors.
To me there is nothing about it that would logically or magically make it reduce throat wear, it would be about equal to giving a car a coat of paint and expecting another 100,000miles out of the engine.
The 2 together might make for better harmonics that could improve accuracy. I would expect this is where much of it is, and some possible placebo effect.
I'd be quite interested to see how the steel and carbon fiber behave together over consecutive firing as the temp rises and stresses change, as I do love experimentation, but it needs real data.