Actually I'm fine with "World" being on PS4/XB1 ... they can keep the "World" series. Capcom whether they admit it or not pulled a fast one on Sony by doing this. Yes they will justify it a million ways publically, but IMO deep down they simply wanted a sweetheart deal from Sony, but also wanted to retain the Monster Hunter 5 name for the Japanese portable market.
I don't buy their excuse for not calling the PS4 game MH5. They knew full well what they're doing. MHW can be the "next mainline MH", but that means dick all in Japan. MH5 will be on Switch.
No game company in the world is dumb enough to end a 4+ million selling franchise.