Engineers are working diligently to fix this issue. There is not an estimated target for the fix; however it is anticipated to be soon.
Other social platforms such as Facebook, Twitter, and LinkedIn do not include that API. Once you select Google+, click the attach link icon. Enter the desired URL, then click the checkbox to begin the web-scraping process. Users then see the title of the page link and a list of thumbnail images to select from using Google+ API.
If you do not want to publish to a Google+ page, you can remove the property after the URL is scraped. Only the desired social properties that you want to publish would then be listed.