They will be referring to part numbers which do change in 2019 and why it shows as incompatible. I had the same issues. However all wheels are interchangeable across the years ranges.
In actual fact the only difference is the button pack which changed along with the update in the software system from SDD to CCG (I think, please correct me if I'm wrong.)
However, the plugs are all the same and it's as simple as unplugging one set of buttons and plugging in the other.
You could just ask them to sell you whatever wheel they do have access to. It will fit, but you'll probably still need the buttons and the heater module.