IA dump of one existing vocabulary term using my processor yeilds the following:
>
>
> schema:StadiumOrArena a rdfs:Class;
> rdfs:label "StadiumOrArena";
> rdfs:comment "A stadium.";
> rdfs:subClassOf schema:CivicStructure,
> schema:SportsActivityLocation .
>
> IMO, just changing rdfs:label to "Stadium or Arena" would work properly. Adding @en would make sense too, opening the door for alternate translations, or content-negotiated based on Accept-Language.
I am not sure this is correct, because the schema.org infrastructure uses the rdfs:label to access the local part of an element's name. Of course, this could also be extracted from the URI. But that will require a careful update of the schema.org scripts because I assume the local part of an element's name is used in many parts of the code.
A quick guess is that at least the breadcrumbs and the name of supertypes plus their cross-links are based ond rdfs:label.
So yes, it can be done, but it will be a significant source of error in the deployment of schema.org.
Martin