Based on some (IMHO) low grade Samsung Galaxy releases (like the A series), they need to partition their high end from their low end.
Keep Galaxy on the high end because its name recognition is already established.
Hire one of those name generation marketing companies to come up with a meaningless name elsewhere (like Celica, Camry and Corolla) and built the name up from scratch.
And how long will that last? Back in the day, Galaxy was the premium brand name. Then Samsung started putting Galaxy on everything down to the kitchen sink. Give it 3 years and that new premium brand name will be on every samsung phone down to the lowest budget phone.
This isn't limited to samsung, I see most companies these days having a hard time keeping consistent brand names. Remember when Lenovo Yoga used to mean laptops with touchscreens and can turn into tablets? Now everything is a Yoga
At issue is likely companies create brand names and it costs money to keep the brand name known. But maintaining a brand name for only a few devices and another brand name for other devices has duplicate costs. Thus, with time they begin to throw in more devices to monetize on the brand and before you know it, the brand means nothing and every device has that brand on it
If they are worried about losing out to iPhone sales perhaps they could call their premium phones Pears? It needs more than a name change to get younger consumers off an iPhone!
Taking a cue from car companies which have standard and luxury brands, Samsung is considering a new brand name for its premium smartphones that may help it to sell more devices. If it goes ahead with the decision, it will be following in the steps of Chinese companies with multiple phone brands.