In the tragic cultural revolution much of the Chinese history was destroyed, temples ransacked, monuments smashed. Now China wants to attract tourism and is rebuilding some of these monuments. There is no way of telling whether you are looking at something that is thousands of years old or something that was rebuilt yesterday.
But then that is true of most historical monuments around the world – from Pompeii to The Grange in Ireland.
The statues in these caves supposedly dated back a thousand years or more. Reconstituted or not they were impressive.