I've set up a test-case which I'm attaching to this post.
I'm using 19.5.493.

I have a very simple skinned and animated cube that I imported from an FBX.
I added some fur to it using the "Add Fur" shelf button under "Hair Utils".
Lastly, I used the "Generate Hair Cards" shelf button to turn the guides into card mesh.

What I was HOPING would happen is that the hair cards would be generated with awesome skinning and ready for export as skeletal mesh to Unreal.
Unfortunately, that's not the case. The hair cards have no skinning and get regenerated every frame (in different locations). See attached video

I just want to confirm that this is expected behavior, and not user-error.

Although there are some usage errors (rest skin should be connected to Guide Groom), I think the "hair Card generate" node has some bug

Interesting. This was all vanilla setup process using nothing but the shelf buttons.. with one exception: I added a "normal" node to the imported base mesh.
I'm not ultra familiar with the hair and grooming workflow, i'm prototyping some fur and was able to navigate the entire process pretty easily. This was the only part that didn't completely work the way i expected it to, so I thought I'd ask here.