Why would it not be OK to replace a map light bulb with an LED?
White LED spectra contains quite a bit of blue range wavelength, which is bad for night vision.  Red light is much better.
The eyes have cone receptors for day time and rod receptors for night vision.  The rods contain rhodopsin, which enables night vision.  It takes about 1/2 hour for enough to build up to have full night vision.
Exposure to shorter wavelengths quickly breaks down rhodopsin, which is why blue light is to be avoided.
Natural sunlight is strong in blue (and UV) spectra.  Incandescent tungsten filaments have much less blue/green spectra, and a lot more orange/red.  So it may be a bit &quot;old school&quot; to shun LEDs.
Newer OLEDs have spectra closer to candles and incandescent.
One interesting measure is how much the light suppresses melatonin, which helps one sleep.  Newer OLEDs were found to be only fractional of blue light, so it would be important to be sure any replacement map light is appropriate for the task.