To be honest, it does look like a 3d stroke effect to me.
Animating the bend, z depth, offset and other factors to create it.
I would start with a straight line as the basis for the stroke. Go to where you want the move to finish and set it up there. Then move back to where you want the animation to start and set up that part. Scrub through and tweak as required.
any advice I give is from my limited experience, therefore probably wrong…
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