I think these started life as Incandescent, but just like most other (incandescent) lights in the park, they were fitted with LEDs as the incandescent bulbs failed. But in some parts of the park, the LEDs would mess with the dimmer based soft start circuitry, causing sets of fixtures to strobe for however long it takes for the dimmer to reach full brightness.
Yeah I think 2012 would be a bit early for LEDs in that form factor. Interesting soft start circuity too, they way they switch on seems to look like they were trying to emulate the old series incandescent lights.