Since when is size 14 considered “plus size”? Size 16, Maybe. Size 18? That’s pretty standard. But size 14??? That’s close to average sized!
I think it can also refer to the cut. It has a more generous cut instead of being form fitting.
https://www.amazon.com/Kara-Womens-Sleeve-Beaded-Silver/dp/B0765KWPW5