“American Horror Story” Season 10 and the Ryan Murphy franchise’s new FX on Hulu spinoff series, “American Horror Stories,” will both debut this summer.“Coming in July, exclusively for FX on Hulu is ‘American Horror Stories,’ a spinoff of our long-running, award-winning hit series ‘American Horror Story,'” FX Networks chief John Landgraf said Tuesday during parent company Disney’s media briefing ahead of its upfront presentation.