assert_called_with only checks against the last call. The docs were have been fixed with issue35946. So after multiple calls the you might get an assertion error in your proposed implementation leading to the conclusion that the call never happened but it's just that the last call doesn't match as explained below. mock calls are recorded in mock_calls attribute so you can do a contains check by constructing the call object to see if the calls are present. For multiple calls you can do a list comprehension and use all().

If it's added it would also mean the addition of assert_not_awaited_with for AsyncMock. Given that there is contains check to do it one line I am not sure it's worthy enough to expand the API. I couldn't find any related proposals in the past. assert_not_called is also a shortcut as added in issue21262. I would wait for others opinion on this.

./python
Python 3.9.0a0 (heads/master:392a13bb93, Oct 16 2019, 22:59:54) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from unittest.mock import Mock, call
>>> m = Mock()
>>> m(1)
<Mock name='mock()' id='140089503302176'>
>>> m(2)
<Mock name='mock()' id='140089503302176'>
>>> m.assert_called_with(1) # Raises AssertionError but the call was actually made.
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/xtreak/stuff/python/cpython/Lib/unittest/mock.py", line 902, in assert_called_with
    raise AssertionError(_error_message()) from cause
AssertionError: expected call not found.
Expected: mock(1)
Actual: mock(2)
>>> call(3) not in m.mock_calls # Use contains check instead of iterating through call_args_list
True
>>> call(1) not in m.mock_calls
False