Aggregation: No bucket for empty field

Continuing the discussion from Aggregation on term is case insensitive (returns term in lowercase):

Enonic version: 6.8.0
OS: Linux

Lets say you have a total hit count of 10.
There is 5 with the value “A”.
And 3 with the value “B”.
And 2 with the value “”.

Aggregation only return buckets for A and B, not for “”.