Applying fades to take folders is not supported. Logic Pro X incorrectly displays the Fade cursor when you mouse over a take folder.
Logic Pro X: Fade tool does not work with take folders
If you select the Fade tool from the Tool Box, the cursor shows the Fade tool when you place it over a take folder on an audio track. If you try to apply a fade to the take folder, the cursor behaves as if it were the arrow tool.