False. NULLs add a level of complexity to value checking.
A NULL value is never = or <> any other value. After all, an unknown value could be 'VALUE1', so SQL can't say that it's "<>".
Also, a WHERE condition(s) must be "TRUE" to include a row, not just "might be TRUE" or "not proven FALSE".
Interestingly, a CHECK condition must be "FALSE" to prevent a row from being INSERTed. If you run the code below, you'll see that the NULL value IS inserted into #t1, even though it seems to break the CHECK constraint.
CREATE TABLE #t1 ( col1 varchar(10) NULL CHECK(col1 <> 'VALUE1') );
INSERT INTO #t1 VALUES('VALUE1') --<<-- not INSERTed
INSERT INTO #t1 VALUES('VALUE2')
INSERT INTO #t1 VALUES(NULL) --<<-- this row *DOES* INSERT
SELECT * FROM #t1
DROP TABLE #t1;