Google Webmaster tools Stopped Content Keywords
Reason for No Content Keywords
Earlier the content keywords feature was the only feature to find , for which all keywords , google bot indexed your content.
Later google implemented Search Analytics . , where google will list where all our contents are listed against which all keywords on user searches., This is enough to confuse between content keywords and analytics and obviously the latter is more clear in terms.
This is the reason to retire Content keywords according to search console official blog
October 17, 2017