Assuming that image indeed shows what people think it shows - well that was quick. 054 ship being at that stage of completion means that the order for new vessels must've been made at least 2 to, possibly, 3 years ago. But we've learned of the additional 054 ships being ordered/planned only weeks ago.
That image should be new. There is another image and the second image shows that sharing the same shed, on the adjacent space, an existing 054A getting overhauled, possibly being upgraded, with the number 573. Pictures of 054A getting their overhauls starting recently, or at least from 2019, so this isn't an old pic from Huangpu Shipyard with 054A coming out of the shed which there is so many in the past during the golden age of their production.
If the hull is already at this stage, I concur the that the decision to make this ship was probably a few years ago. Maybe the batch ordered was small, probably 4 to 5, like the last batch, and this order has been expanded to another 20.