I reckon there is a reason. Every title Funimation have announced this past year is from their Kadokawa deal; The Betrayal Knows My Name, Good Luck! Ninomiya-kun, Gosick, Hyouka, The Mystic Archives of Dantalian, Nichijou, Omamori Himari, Record of Lodoss War, Scrapped Princess, Sekai Ichi Hatsukoi: The World's Greatest First Love and probably many more (perhaps even The Slayers Movie & OVAs).
All have been confirmed region locked and are not streaming for the UK, so it's quite possible that someone in the UK could have a similar deal so Anime Limited for example since they and Kadokawa get along pretty well.