Discussion about the Korg PolySix synthesizer

I wonder if the actual replcement of the resistor when converting the 
battery typr from NiCD to Lithium on the Polysix as an actualy reason -
in other words, in case I'd keep the resistor and connect the diode 
between the battery and the resistor - would that be a problem ? 
is replacing the resistor done only so the diode phisically fits in the 
circuit, but also no need to the resistor anymore as the battery is not 
charged ?