set status to Delayed, set type to Feature Request, made ticket public.
This is how the model is in Bedrock, which is where the models are pulled from. I'm hoping they synchronize them at some point but I don't know if there's much of a good solution for this one without splitting it into two different models, which would affect all the back-catalog of skins.
I'll leave this delayed, just in case people want this to be fixed, but I think it's super low priority.
Slim models arms are not aligned with torso.