Current consumer LCDs, sure, but there's no realson a high-refresh-rate LCD couldn't emulate the flying spot of a CRT, and thus be compatible with light pens / guns.
In order for that to work, it’d need to be able to switch individual pixels in sequence, one at a time. The display panel would need to be designed for this - current panels aren’t, but as long as a screen position could switch to 100% in about 250ns, a sensor could tell precisely which pixel it’s looking at.
Liquid crystals cannot switch from 0 to 100% in less than 10ms, never mind 250ns. They’re electromechanical devices that need to physically twist/untwist to affect the polarization of light.
Contrast that with a CRT which uses a 25kV acceleration voltage to drive an electron beam up to 30% the speed of light (takes about 3.3 nanoseconds to travel 1 foot from the back of the CRT to the screen), which then strikes a phosphor that glows due to its valence electrons falling from excited states (which takes a few nanoseconds).
