We have a similar drill in YCW WC. We call it Double Circling Hands. It has aspects of pummeling, it's a key component of Kum Na.Woon or wun-sau refers to the circling changes in chi-sau, like huen-sau. We also use the term for a circling-hand chi-sau platform similar to what you presented except with smaller movements, keeping the hands closer in towards center --never moving laterally. The way we train it, the circling movement isn't initiated by the practitioner, it is used in response to circle around pressure from your partner and recover your attacking line while maintaining forward intent. Chasing hands laterally would be considered a serious error in the drill we do.