Microsoft Advertising's broad match modifier keywords are now being served as broad match keywords instead of phrase match on Bing Search. This is effective as of yesterday, March 15, 2023.
Microsoft posted a note about this saying "Please note: All broad match modifier keywords for search ads now serve as broad match keywords instead of phrase match."
Broad match is the default keyword match type that makes your ad eligible to be displayed when someone searches words related to your keyword, which can include searches that don't contain the keyword terms. Broad match will also match synonyms and other similar keywords, including those with spelling errors.
Nicole Farley reports, "This change could affect the way ads will be served on the Microsoft platform. Broad match modifier (BMM) keywords will now serve as broad match, which means that the keywords will match with a wider range of search queries. This change can impact the relevance and quality of the ads shown to users, as well as the cost and efficiency of their advertising campaigns."
So if you are using this match type for search on Microsoft Advertising, please note this change.
Forum discussion at Twitter.