Non-root exit animations not animating

[rorticus]

Bug

Exit animations are not playing if the node with the animation is a child of a node being removed.

Package Version: 7.0.0-alpha.6

Code

1. Wait for the fade-in animation to complete.
2. Click Toggle and notice that there is no exit animation (it should fade-out)

https://codesandbox.io/s/goofy-thunder-30r5v

Expected behavior:

The entire subtree containing an animated node remains in the DOM until the animation is complete.

Actual behavior:

The node is being removed from the DOM immediately and the animation cannot play.