I would say that a DTO is a POJO that is setup for the exclusive purpose of being transmitted to and from a datasource. So I would say that if you plan on using the POJO just for transmitting to and from a datasource, then I would call it a DTO. That would let me know what its purpose is for. If the POJO is going to be used for other things beyond just transmitting to and from a datasource, than I would call it a POJO.
Typically I do not see these terms used much anymore. Now I just see POJO and they typically go into a package with the name "model" or "domain". If I see these packages in a project, I know these are POJO's that can be used for business logic or transmitting.
Why its probably not a VO: VO's are small objects, like coordinates, or money. They are immutable and do not contain many fields. So not really something with multiple fields that you would require JSONshema2pojo. Though when parsing a large JSON, JSONschema2pojo might create many little classes that fit this definition.
EDIT: This is all subjective. And only providing an opinion here.