none said:

Alexrd wrote: That doesn't necessarily contradict what he said. Either with puppet or digital Yoda, they were going to need Frank Oz.

Yes history shows they have kept his voice. Would you now consider his TPM puppetry work as pre-viz?

No. But I think they said that (on the making of book) after they had decided to go with the puppet. Either way, it doesn't mean they hadn't considered a digital version. After all, they did use it on a scene on the original version of the movie.