JWWC said:They are all susceptible to rust at this point just to varying degrees.

Some do show significant resistance compared to others, and that is considered to be a good thing (for plants and people, both).

There's no shame, and much joy, in applauding cultivars and hybridizer's work done prior to awareness about plant diseases, and as explained, it sounds like it takes some years for most to get to the Stout nomination level.

Current hybridizers have shown good use of the rust performance data that was generated with AHS's support, by selecting toward resistance for rust. The explanation for resistance scores and what they mean is Here.

Just as important is information on resistance to the fungus that is associated with leaf streak and spring sickness. There were also hundreds of cultivars that were tested and scored for performance with that fungus, and a link to the findings are Here.