While airlines will 'train' for a standard visual circuit, in real life it is extremely rare to see such an animal. Most visuals require a lot of effort in planning as many airports impose different 'constraints' on ground tracks or altitudes for these, and it would not be economic for airlines to 'train' for too many specific airfields. Perhaps the commonest event, 'joining downwind', is rarely conducted iaw the 'standard base training' circuit, since it would take far too long to fly!
As 'ralph' says, it is a sad day if the skill 'disappears', and one hopes that Captains will always help and encourage their F/Os to fly varying visual circuits when conditions permit. If they do not, then the 'Captains of the future' will not have the skill.