From Tamron:
Dear users and potential purchasers of Tamron interchangeable lenses.
Thank you for using Tamron products and for your continuous support.
We would like to announce that we have clarified compatibility in general operations(*1) of following Tamron Di & Di II lenses on Canon EOS R, which was newly released on October 25, 2018, with Canon Mount Adapter(*2).
Compatible models in general operations(*3)
(*1) Defined to work on existing DSLR cameras
(*2) Canon "Mount Adapter EF-EOS R"
(*3) With the latest version of lens firmware
About other Tamron models, we will make a further announcement of the compatibility at our support web page once the operation tests are completed.
Thank you for your patience and understanding in this matter.