I guess it’s been somewhat forgotten but Google Plus should be removed from *.lang.json file of all themes:
"shareButtons": {
"shareWithFacebook": "Facebook",
"shareWithTwitter": "Twitter",
"shareWithGooglePlus": "Google Plus",
"shareWithPinterest": "Pinterest",
"shareWithStumbleUpon": "StumbleUpon",
"shareWithLinkedIn": "LinkedIn",
"shareWithBuffer": "Buffer"
},