The ubiquitous Michelin map and the blue IGN maps are all out of date - I suspect it will take sometime for them to catch up! Those clever online people at RouteYou, Mapmyride and Google maps are of course up to date.
Over the past few months the Collectivité Territoriale de Corse has quietly been removing all of the red Routes Nationales signage and replacing them with shiney new Routes Territoriales signage as shown in the picture. Gone is the N196 Ajaccio - Bonifacio and in is the T40, the N200 is now the T50 - all in all there are five principal T routes and a further fourteen subsidiary T routes.
I'm in the process of amending my website text to reflect the new physical T signage whilst retaining the historic N signage, which is most likely what you'll still be searching for based on the maps you have to hand! Fortunately my route maps are current care of RouteYou.