"Nobody knows?" We don't know that for sure. Perhaps GR told a secretary or somebody. But perhaps it is unknowable now.
2. If someone asked, "Why do you THINK GR changed the name..." then have at it, seriously. Discuss away. But I've run into this on this bbs when I really want to know an answer and then have to weed through many speculations. I can speculate myself, or seek some possibilities, but when you gotta know, you gotta KNOW; or find out that the answer is not known.
Like why Theiss didn't switch to a swatch (ok, bolt, I couldn't avoid the word play) that photographed green when the film cam back showing gold/buff. That answer seems to be unknowable. And I can live with that.