In the UK, “asian” is newspeak for muslim in these situations, correct?
Not quite - ‘Asian’ has long been the standard term in Britain for people originating from the Indian subcontinent. It thus includes Hindus, Sikhs, Buddhists etc as well as Muslims.
Indeed, mostly they are Pakistani muslims. But since most media-outlets are leftists they rather say ‘asian’s then Pakistani’s, since using the last one would also automaticly mean they are muslims. And since muslims are members of the Religion of Peace(tm) the left loves them so much.