Would occlusal adjustment lead to cavities developing?

Maybe: Maybe of during occlusal adjustment, the softer dentin was exposed. Dentin would be more prone to decay that enamel.

Possibly: Hopefully the adjustment is conservative without removing much enamel. If too much of the tooth is ground down, then the tooth may be more susceptible to decay. Make sure you keep teeth super clean. Fluoride rinses/gels may help.

Usually not: If done properly, on a patient with normal to good oral hygiene, mild/light occlusal adjustment will not lead to increase development of cavities. Heavy occlusal adjustments, that expose the underlying dentin, should not be done as they will increase risk of tooth decay.