too-many-ancestors when inheriting from collections.abc.MutableSequence

[Alphadelta14]

Simply inheriting from collections.abc.MutableSequence generates a too-many-ancestors refactoring warning.
Yes, it does have that many ancestors, but I would consider only classes from the stdlib that are actually inherited by user code to be counted towards max ancestors.
And yes, I can disable this error in this case, or increase the max ancestors count, but it feels wrong to do that when just using the collections hierarchy for its intended purpose.

Steps to reproduce

For a minimal MutableSequence implemented, ancestor.py:

from collections.abc import MutableSequence


class ItemSequence(MutableSequence):
    """Minimal MutableSequence."""
    def __getitem__(self, key):
        return key

    def __setitem__(self, key, value):
        _ = key, value

    def __delitem__(self, key):
        _ = key

    def insert(self, index, value):
        _ = index, value

    def __len__(self):
        return 1

pylint ancestor.py returns:
ancestor.py:4:0: R0901: Too many ancestors (8/7) (too-many-ancestors)

Expected behavior

Inheriting from a stdlib class shouldn't generate a Refactor warning.

pylint --version output

Result of pylint --version output:

pylint 2.7.4
astroid 2.5.2
Python 3.7.7 (default, Aug  8 2019, 00:00:00) 
[GCC 8.3.1 20190311 (Red Hat 8.3.1-3)]

[Pierre-Sassoulas]

I agree. This is a side effect of a better comprehension of stdlib class in astroid.