Well, it's a bit more complex than that.
First of all, in terms of launch rate, considering 055 unit 1 was launched late June last year, if DL launches its current 2 055s (aka 055 unit 3 and unit 4 overall) before June 28 or 29, then they already technically would've had launched 4 such ships over the span of a year.
In terms of the actual additional 055s under work.... satellite photos of JN confirms that modules for a 5th unit overall is present (aka JN 055 number 3). Satellite photos of DL also confirms that modules for a 6th unit overall is present (aka DL 055 number 3) -- however, given that DL built 055 unit 3 and unit 4 together alongside each other, I cannot help but wonder whether the modules for the "6th unit" at DL may actually end up being modules for unit "6 and 7".
There's also the fact that DL's large drydock where 055s are assembled is also working on two 052Ds, which will probably only be launched later this year or early next year, and considering it took DL 1.5 years to go from seeing modules of two 055s to launching them (soon), I expect it will be late 2019 when DL launches 055 unit 6 and 7.
Over at JN it is a similar but different situation, as they are also working on 052Ds as well as 055s on the same production line, so we won't be seeing consistent 055s launched over at least the next year, but instead see 055s and 052Ds launched in a semi alternating sequence.
So, after DL launches 055 unit 3 and 4 in the next few weeks/days, I suspect the subsequent 055s will come from JN with at least 1 055 being launched from there, before DL launches two 055s again in late 2019.
But in between all that, JN and DL will both launch some additional 052Ds that we can see under work as well.
All a bit of a mess.
