I have no idea what those numbers mean 🤣
We've all seen significant improvements from Ferrari, Alpine and Red Bull Powertrains/Honda engines, all catching up on their overall performance deficit to Mercedes. This would probably be coded in the game somehow following Codemasters' analysis of real world data even if we didn't have different cars to account for.
And as Greco said on his interview, even if we didn't have any regs changes the handling would still be different as they fine tune how all the different parts of the engine work together. It's a huge tapestry of interconnected systems, changing one interaction here has knock on effects to a whole different performance aspect over there. Like how changing the coefficient of grip, be it raw values or its scale or even how the engine operates with it, can output not only a different cornering performance but also straight line top speed.
Even of nothing else changed and the default values you see in the moddable game files were kept the same, if Codies changed the inner workings of the engine we would still see a different performance. And looks like they have done meaningful changes to the code, with proper sim of aero components and tyre model and so on and on.