The American Bar Association recently streamlined its ethics rules on lawyer advertising, but proponents and critics agree the changes could have been more extensive.

The driving force for the revisions was “three trends that call for simplicity and uniformity” in regulating lawyer advertising—cross-border practice, increased use of social media and the internet, and growing concerns that restrictions on truthful legal ads could be problematic under the First Amendment and antitrust law, according to the ABA’s Standing Committee on Ethics and...