BUG: CoW - eq not implemented for <class 'pandas.core.internals.blocks.ExtensionBlock'>

[mhabets]

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Reproducible Example

import pandas as pd
pd.options.mode.copy_on_write = True

idx = pd.Index(['a', 'b', 'c'], dtype="string[pyarrow]")
pd.Series(idx).replace({"z": "b", "a": "d"})

Issue Description

The above code raises the following issue:
NotImplementedError: eq not implemented for <class 'pandas.core.internals.blocks.ExtensionBlock'>

Expected Behavior

The code should run without raising any error as it does without the CoW clause, shouldn't it?

Installed Versions

INSTALLED VERSIONS

commit : 2cc3762
python : 3.12.5
python-bits : 64
OS : Windows
OS-release : 11
Version : 10.0.26100
machine : AMD64
processor : Intel64 Family 6 Model 154 Stepping 3, GenuineIntel
byteorder : little
LC_ALL : None
LANG : en
LOCALE : English_United Kingdom.1252

pandas : 2.3.0
numpy : 2.1.3
pytz : 2024.1
dateutil : 2.9.0
pip : 24.2
Cython : None
sphinx : None
IPython : 8.32.0
adbc-driver-postgresql: None
adbc-driver-sqlite : None
bs4 : 4.12.3
blosc : None
bottleneck : None
dataframe-api-compat : None
fastparquet : None
fsspec : None
html5lib : 1.1
hypothesis : None
gcsfs : None
jinja2 : 3.1.4
lxml.etree : 5.3.0
matplotlib : 3.9.2
numba : None
numexpr : None
odfpy : None
openpyxl : 3.1.5
pandas_gbq : None
psycopg2 : 2.9.9
pymysql : None
pyarrow : 17.0.0
pyreadstat : None
pytest : None
python-calamine : None
pyxlsb : None
s3fs : None
scipy : 1.14.0
sqlalchemy : 2.0.35
tables : None
tabulate : None
xarray : None
xlrd : 2.0.1
xlsxwriter : 3.2.0
zstandard : 0.23.0
tzdata : 2024.1
qtpy : None
pyqt5 : None