6 Type 09IVs in service was more or less confirmed with high confidence a few months ago, if I remember correctly, when satellites and other imagery caught all 6 at different locations simultaneously.
Makes sense for this to be the seventh.
But I would not trust English language literature, including Wikipedia, to keep track of these boats based on pennant numbers. It was only by a stroke of luck last year that we could guess, with persuasive evidence from civilian satellite imagery and enthusiast photographs, that there were 6 boats in service.
The latest Type 094A variant is commissioned as the 'Long March 18'.
According to this post, this is a new variant of the Type 094 class, but I cannot find the difference or changes.
Variant 1: Three rows of drainage channels, observation window on the front of the sail.
Variant 2: Three rows of drainage, observation window on top of the sail.
Variant 3: One row of drainage, more streamlined transition from the bow to the bulge amidships.
Variant 4: Two rows of drainage, bulge has become bulkier again, perhaps to accommodate JL-3?