Hey guys,
when using Roost, it "heals" status on your Pokemon, but only visually. I tested this with a Magikarp using Roost while the Blissey used Will-o-Wisp to burn me.
The Burn status icon got removed once I used Roost. However, I was still burned, so it's just a visual bug.
This does not work at full HP, only if you took damage and use Roost.
https://gyazo.com/74291a423608d2153affd11bb84f8ddf Still taking burn damage but the Burn icon isn't there anymore.
This also works with other status, such as poison from Toxic.
https://gyazo.com/e1f036859e3a7693d5b87fd15f5fcfe9 Using the status move again displays the message that you're already status'ed, so yeah.
Thank you for reading,
~Kirby