value_counts does not respect ordered categoricals

[jpeacock29]

Code Sample, a copy-pastable example if possible

import pandas as pd

cat = pd.Series(pd.Categorical(
                ['a', 'c', 'a', 'b', 'a'],
                categories=['a', 'b', 'c'],
                ordered=True))

cat.value_counts()

Problem description

This outputs the value counts in the order 'a', 'c', 'b' when the categorical is ordered 'a', 'b', 'c'. value_counts should respect ordered categoricals and display them appropriately.

Expected Output

value_counts outputs in the specified order: 'a', 'b', 'c'

Output of pd.show_versions()

INSTALLED VERSIONS

commit : None
python : 3.7.4.final.0
python-bits : 64
OS : Darwin
OS-release : 18.6.0
machine : x86_64
processor : i386
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8

pandas : 0.25.0
numpy : 1.17.0
pytz : 2019.1
dateutil : 2.7.5
pip : 19.2.1
setuptools : 41.0.1
Cython : None
pytest : None
hypothesis : None
sphinx : None
blosc : None
feather : None
xlsxwriter : None
lxml.etree : 4.3.0
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : 2.10
IPython : 7.2.0
pandas_datareader: None
bs4 : None
bottleneck : None
fastparquet : None
gcsfs : None
lxml.etree : 4.3.0
matplotlib : 3.1.1
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : None
pytables : None
s3fs : None
scipy : None
sqlalchemy : None
tables : None
xarray : None
xlrd : None
xlwt : None
xlsxwriter : None

[WillAyd]

Thanks but this is at its core a duplicate of #12679 . Closing for now to keep discussion and tracking material in original issue