(Q) ListItem.Art(thumb) empty if Episode Thumbs are not enabled?

Like the description above.
My question is:
Is ListItem.Art(thumb) empty, when "Spoiler-Thumbs" are disabled? Shouldn't it be "OverlaySpoiler.png" instead?
If I disable "Thumbs" to prevent spoilers, then ListItem.Art(thumb) gives nothing back.

Reading this merged PR (VideoThumbLoader.ccp) then it should display "OverlaySpoiler.png"
https://github.com/xbmc/xbmc/pull/14971/...0d0f3432b5

What I am missing? What am I doing wrong?
Thx