It looks most similar to a Rhodes piano-type electromechanical keyboard, where tuned metal elements are somehow actuated and then sonified with a guitar pickup. Unlikely theres any FM which would require independently digitizing each of the resonators and just generally a lot of complexity that doesnt seem warranted.

The similarity in timbre isn't coincidental though -- FM is noted for its ability to emulate complex timbres like bells/metallic tones (such as electric pianos) that are challenging for more traditional subtractive synthesis architectures.