Yeah I guess with GIFs that have "transparency", it's all about whether the recipient can decode the transparent background and do background matting.
Also I know we talked about white background but the background can be any color and the best way to get a clean "transparent' GIF is to make sure the background color is not present in the animation which is way I mentioned using chroma green or blue typical to a green screen effect.
As a note, Photoshop does support GIF transparency but After Effects & Premiere Pro don't so you have to key the background.
