there are 2 things made of ferrite in an adapter, for different reasons. There is a ferrite ring around the input cable so that EMI don't go upstream in the soc

there are 2 things made of ferrite in an adapter, for different reasons. There is a ferrite ring around the input cable so that EMI don't go upstream in the socket, and this one they will probably keep. The other one is the core of the transformer and they say they don't need it at that frequency.