Today, it's impossible to tell if Sky van Hoff will be Rammstein's producer for the new album, instead of Jacob Hellner, Rammstein's traditional producer. It's possible that Rammstein is only trying new things, as they indicated in a interview last month:
This actually happened, it's an absolute blast for me as a musician, music producer, human being to work with a band I've been listening to since I was about 13 years old. A great week in Berlin with even better people! More to come!
We even try unusual methods, new ideas, and change the path that one usually has. We might consider another producer.