Hi Paul,
I have no experience or knowledge about the Win 10 IoT core platform, but that said any platform or application that exposed an API layer (SOAP or REST) can be integrated with OutSystems. There is plenty of documentation and training material on this subject, for example:
https://www.outsystems.com/training/courses/116/integrating-with-web-services/
The Forge has also components to integrate using MQTT, see:
https://www.outsystems.com/forge/list?q=mqtt&t=&o=most-popular&tr=False&oss=False&c=%20&a=&v=&hd=False&tn=&scat=forge
Regards,
Daniel