Alternative way to represent to open or close a dropdown?

I'm doing some animation icons for a recent product and I'm playing with some alternative to the standard dropdown toggle. Typically, it's a arrow pointing either down or up...

Is there any reason to not have it a chevron down and then an X icon to close? Would this impact any user expectations or the web standards / what people are used to?

Here's an example of what I'm suggesting: https://codepen.io/brycesnyder/pen/XWWbZEz