「上架」不是On the shelf
I've had to shelve my plans to buy a new car, because I can't afford it at the moment.
"On the shelf"是"postponed"，延遲擱置的意思
These proposals have been on the shelf from six months to a year.
"On the shelf"也有"not socially active"閑置，甚至有結婚無望的意思
In those days, if you hadn't married by the time you were 30, you were definitely on the shelf.
因此＂It is already on the shelf＂真的容易會錯意
This product has already hit the store shelves. （這個產品已經開始販售）
This product is launched already. （這個產品已經發表）