SEAT R line cars were 'EXCLUSIVELY' built/prepared (mainly prepared) by SEAT Sport.
The Cupra R
Ibiza & then the Cupra R Leon were produced mainly because SEAT Sport had left the WRC and had no other Motorsport commitments at the time. So they used the Motorsport team to trick up their top road cars.
Since they entered into World Touring Cars, and BTCC, as well as customer touring cars. As well as the SEAT Cupra Championship which is currently run's in several countries, inluding Spain, UK, Germany, Turkey and Italy all requiring cars to be built and parts supplied to their motorsport customers.
As a result any further 'R' spec cars are a unlikely to be forthcoming anytime soon.
The press pack for the Leon Cupra, makes a point of this very fact. Saying no Leon Cupra R version is forthcoming anytime soon.
They'll never say never, but it's highly unlikely they will be producing an Leon Cupra R in the next couple of years.