There is typically a hard current limit of 32 Amps. (but depending on the EVSE, the supply may assert a lower limit, which the car must obey)
But it will take whatever voltage it gets. You have little direct control over that. 240V is optimistic. That assumes limited upstream losses. At current, 230V is more typical. In an industrial location 208V is common (one branch of a 3-phase supply) which gets loaded dow to ~205V.
240V => 7.68kW
230V => 7.36kw
220V => 7.04kw
205V => 6.56kw
So I think they pick 7.2kw as a 'typical' input power.
Another possible explaination is that 7.2kw is the power delivered to the battery, after accounting for ~6% conversion losses in the on board charger.
Worry about the current, not the power. The car can take up to 32 Amps, so for fastest Level 2 charging make sure you are using a 40 Amp or larger breaker to feed a 32Amp or larger EVSE.
At home, you should look at the voltage losses in your home wiringing. The voltage at the EVSE will always be a little lower than at the power meter. A small drop is unavoidable, but if the voltage drop flucturates, or is higher on one leg of the 240V circuit than the other, you potentially have a wiring problem. At best, the voltage drop is costing you money because you are paying to heat your walls. At worst, that heat is concentrated at a bad connection somewhere and could start a fire)