The Clouds forecast overlay on the Map and Profile View are based on the GFS Cloud Coverage product. The timestamp on the Maps page is the model time, which is the start of the validity period for the forecast.
The timestamp in the Profile View is the time when ForeFlight received and processed the data. The GFS Cloud Coverage product has about a five-hour delay from the model validity time to when the data is published. Once the data is published, ForeFlight receives the information and processes it for display in the app.