No, the ECMWF weather forecasts are not available through Copernicus. Essentially ECMWF's activities to implement the CAMS and C3S Copernicus services are separate from ECMWF's mandate to produce weather forecasts.
Some ECMWF products are publicly available for free. Others, in particular the 10 and 15 day forecasts, are only available to specific user groups or for a fee. For further information see here.
