Yes we do. I have observed this when I was modeling in python sklearn. So I decided to ignore those. Here querys comparing counts of register with nulls and without nulls:

7631 (including nulls)

7504 (excluding nulls)

SELECT count(id) FROM Community.Post order by id

Result

Namespace: PYTHON

Result #1

Aggregate_1
7631

1 row(s) affected

2020-07-20 01:48:27  Routine: %sqlcq.PYTHON.cls264

SELECT count(id) FROM Community.Post Where not text is null order by id

Result

Namespace: PYTHON

Result #1

Aggregate_1
7504

1 row(s) affected