...there's no outright ban of r-compounds in the works, rather new street-legal restrictions will likely limit poor wet performance tires to track use only...
...all that means that streetable track tires will get more conventional tread patterns for better wet performance, at a slight penalty of ultimate grip, but r-compounds are not at risk for street applications so long as they meet minimum rolling resistance standards...i expect that the selection of track-only tires will also improve as a result of increased demand, without street-legal tread pattern requirements to compromise their design...