Japan’s new MNO entrant, Rakuten Mobile, has maintained hugely high profile for the whole of the past year, as the poster child for how a greenfield operator can deploy new cloud-native architectures in order to transform the conventional cost base of the mobile network. Excitement about what Rakuten is trying to do has almost overshadowed launch delays – themselves a sign of just how difficult this type of deployment is – and doubts thrown over its low-capex predictions by its rivals. Other operators, especially new entrants like Dish Network in the US and Reliance Jio in India, have raced to pledge similar architectures and cost reductions. Now, finally, Rakuten has given a date, April 8, and information about services and…