Catching API changes for a service that doesn't version its API
Some comments:


Instead of using print statements, the logging module could be used
The return value of get_google_content should be a boolean value (True on success, False on failure)


Regarding ways to make the refresh_content method a little bit more pythonic, I would probably use a for loop and the all built-in function to make sure that all the calls to get_google_content  were successful.

@app.route('/admin/refresh_content')
def refresh_content():
    spreadsheet_keys = ['key_1', 'key_2', 'key_3']
    tables = [Table1, Table2, Table3]
    sheet_statuses = [
      get_google_content(spreadsheet_key, table)
      for spreadsheet_key, table
      in zip(spreadsheet_keys, tables)
    ]

    if all(sheet_statuses):
        return '&lt;h1&gt;Success&lt;/h1&gt;&lt;br&gt;Updated spreadsheets'
    else:
        return '&lt;h1&gt;Failure&lt;/h1&gt;&lt;br&gt;Unable to update all spreadsheets'


There are other strategies, but that depends on different things like whether you want to stop on the first failure or not.

I hope this helps.