Hey, you think it's normal to have different currents for different voltages. But with PD it isn't. It maxes out the current at 3A with any voltage, except the highest supported one. For example, 45W means 3A up to 15V and (I suppose) maybe optonally 2.25A with 20V.
Allowing higher current than 3A could cause the cable to overheat, or it simply wouldn't work out with a cable of higher resistance, because too much energy is lost to heat. That's why it's out of spec.
So, in the world of USB-PD, it's an exception to have different max current for different voltages. An exception for the highest supported voltage, because everything else is limited to the very same 3A, and that's why it's highlighted in the spec.
As for removing doubts, we should go with the latest news we have. So it's 45W, which means up to 15V. And maybe 20V, it's a bit more economical (lower current means less energy loss) but financially doesn't make much sense because the charger is more expensive.