So its just a classification.
All of the various manufacturers in the link produce model kits that are intended to be built as radio controlled models. Some fall into the "throw the bits sort of together" variety, others are"you need to read the instructions and actually do some modelling" type, and everything between. Certainly the UK produced ones were designed and built and tested as radio controlled models, often by the manufacturer. Such is the nature of the UK "cottage industry" nature of model boat kits.
A real thing that was an awkward sailer might well do the same for a model. A well behaved real one has a good chance of producing a well behaved model. As an instance, the "Sir Kay" makes a superb working model, but needs very careful fitting out, as it can be very tender. A poor layout results in an unstable boat.