Two reasons.
Eggplant and teal were very, very 90s colours. As we got into the 200s they started to look very, very dated. So there was a move to distance them from that very specific look.
Also - the entire look was very linked to the previous owners, Disney - in a way I don't think we've ever really seen before. So the new ownership wanted to distance themselves from a look that screamed "Disney".
Now, everything old is new again. The 90s are 30 years ago, so now eggplant and teal are kind-of interesting again. Nostalgia is a hell of a drug.
But the thing is - orange is a pretty strong colour too, and not much used (not like the countless blue teams), so it's not a bad option to keep either. And while their 2007 win wasn't in predominantly orange jerseys, they did use it as an accent back then.
Distinctive isn’t necessarily cool. To many the original was embarrassing. Disney made a mockery of their pro sports franchises and distancing from that is fine
The Bruins' color scheme was designed to match the theme of the grocery store chain their then-owner also owned. Their identity is grocery store branding.
The Flyers are orange because one of their early investors went to the University of Texas. No real rhyme or reason.
The Calgary Flames' name and scheme was the result of Sherman burning down the city of Atlanta in 1864. Looks great, sounds cool.
The Rangers name is an homage to a faraway law enforcement unit incorporated 200 years ago to kill Native Americans and Mexicans. In case you were wondering.
The Winnipeg Jets were named after the NFL's New York Jets. Seriously.
The list goes on and on and on. The origin of Anaheim's franchise was campy. There's nothing wrong with camp when you compare it to the above.
All these things fade into memory or become silly anecdotes. The people who recall the bad years or the source of the reference will all age out and die. You can't choose where shit comes from, but once it's there, you gotta look at it and decide if it works or if it doesn't. Eggplant and teal was unique and it did, in fact, work.
If they wanted total distance from the Disney years, they wouldn't be the Ducks anymore. But they are. They wouldn't use the duck mask logo. But they do. They've kept elements of that initial branding but thrown away the half that gave them a distinctive identity. They're now 30 years in and still trying to figure that out. Take what legacy you have and lean into it—don't keep trying to change the outfits and hope something sticks (*cough* Vancouver).