No, > /dev/null 2>&1 is. If try your example but with file instead null, stderr content not in file.

Because x>y not redirect x to y, but duplicate y and set x to y-duplicate. See bash manpage REDIRECTION (your example in that section for what not work).

As i understand, your example set 2 to what 1 is, then set 1 to null. Now 2 not null, but what 1 before.