We recently published an article that reported that Kojima was currently in the process of searching for a game studio to develop the original Metal Gear Solid using the same game engine that Metal Gear Solid 5 is utilizing, this being the Fox Engine. Sadly, it has been reported that this information was the cause of a simple mistranslation from a past interview.
As reported by ComputerAndVideogames, Kojima has responded on this matter through his official Twitter account.
But, hope is not completely lost, as Kojima also supplied the following statement:
What Metal Gear Solid title do you want to see make a return with the Fox Engine?