convert text to outlines with gradient fill - BUG

First, don't outline text. It's not a good idea. A lot more than just the fill changes.

But if you like the way Illustrator does it, do it in Illustrator and place it in InDesign.

When you apply a gradient to text the gradient is based on the text frame, not the text itself. Imagine a black to white gradient applied to a text frame. White on left, black on the right. If you apply the same gradient to text in that text frame the gradient will be in the same position. The text acts like a mask on the gradient. Still white on the left of the text frame and black on the right of the text frame. If I convert the text to outlines it is no longer text. It does not act like a mask on a gradient to the text frame because there is no text frame. Since the text is now an object the gradient behaves normally.

This is not a bug but it is a poor implementation of gradients on text. I do not know what Adobe was thinking when they decided this is how gradients should be applied to text. I also do not know what they were thinking every time they updated InDesign and left this crummy gradient feature as is.

I don't this is so much a bug - it's more of a difference between a text paragraph and the grouped text object that results from outlining text. 

For a quick fix, ungroup the outlined text,  use Pathfinder > Add. Then change the color to something else, and back again to the chosen gradient.