Whatever happened to Radaghast?

[Gordis]

Found something in HOME 7.

Home 7: "the story foreseen from Moria"
Gandalf takes [Saruman's] staff and breaks it over his knee. 'Go, Saruman,' he said, 'and beg from the charitable for a day's digging.'
Isengard is given to the Dwarves. Or to Radagast?
They ride home to Rivendell.

Here is some proof that at least at the time of writing of this outline, Tolkien expected Radagast to survive the War of the Ring and remain in ME.