I always figured it was because of the change in ownership. I did a quick AI background research and that was essentially confirmed.

AI:

The Mighty Ducks of Anaheim changed their branding, uniforms, and name to the Anaheim Ducks for several reasons:

Ownership Change: The Walt Disney Company, which founded and owned the team, sold it to Henry and Susan Samueli in 2005. The new ownership wanted to establish their own identity for the franchise separate from Disney.

Rebranding Effort: The rebranding was part of a broader effort to create a more mature and serious image for the team. The original branding was closely tied to Disney's 1992 movie "The Mighty Ducks" and was seen as more youth-oriented and entertainment-focused.

Market Appeal: By adopting a new name and look, the team aimed to broaden its appeal to a wider audience, including more traditional hockey fans who might not connect with the Disney-themed branding.

Fresh Start: The name change symbolized a fresh start for the franchise under new management, which included efforts to build a stronger, more competitive team. The new branding was unveiled before the 2006-2007 season, which coincided with the team winning their first Stanley Cup in 2007.

The changes included a more streamlined and aggressive-looking logo, new team colors, and updated uniforms. The shift from the Mighty Ducks to the Anaheim Ducks marked a significant evolution in the team's identity, aligning it more closely with conventional professional sports branding.