I think the 0.002% is an accuracy specification at 20℃, but not precision.
Precision: Closeness of agreement between independent measurements under stipulated conditions.
Accuracy: Closeness of agreement between a measurement result and the true value.
Such as DVM 34401:
You can find the accuracy spec at 23℃. And it have another spec "Temperature Coefficient/℃" over all temperature range.
So I think AD8421 can satisfy the requirement from you.