In what sort of application would the neutral be switched? Just curious.
Technically, a neutral does not have to be a grounded conductor, although with very few exceptions the NEC requires the neutral of a system that has one to be grounded.
So if the neutral is not grounded, it must be switched both by disconnect switches and by OCPDs that are required to open all ungrounded conductors.
The most common case in which a neutral is switched, however, is when an automatic or manual transfer switch replaces the service as a power source with a supply that is considered an SDS. Since the SDS will have its own ground-neutral bond, the TS must disconnect the load neutral from the ground-neutral bond which is located on the service side.