On January 4, Google released a report that those who are auto-applied to “remove redundant keyword” features, enable this feature on 19 january. They also mentioned a few reasons for this update.
What is Google Redundant Keyword Feature
Previously Google has a feature called “redundant keyword suggestion” which advertisers are using to filter keywords. What I mean is advertisers are using this feature to remove the same type of keywords in their ads.
Previously Google’s redundant keywords feature only removes the same match type keywords from the same ad groups but now they changed the criteria. Now it will remove all same match type keywords as well as other keywords which a broad keyword covers.
For example, in your ad, there are phrases like women’s shoes and the broad keyword is lady’s shoes then google will remove the women’s shoe keyword because the broad keyword covers this keyword.