Not really a confirmation, but this is what Tamron had to say in a recent interview on their plans to develop mirrorless lenses for Nikon Z mount (pretty much the same response they gave a month ago):
Q: Do you have plans to create lenses for Canon RF and Nikon Z?
A: Yes, we’re also looking at that area. We have to do a lot of research and development into the reverse engineering, because they don’t disclose the details of their systems, so it’s a really hard job for us.
Tamron is still exploring the possibility of developing mirrorless lenses for Nikon Z-mount
Via Dpreview
