There wasn't any change to the Rancor raid besides implementing a better tie breaker mechanism. IMO, all they're doing is making territory battles end game content. Heroic Tank is no longer the end game raid. Newer players/guilds will still have it as a stepping stone, something they have to climb and conquer together.
Think of it as a mountain climbing expedition. Rancor was your Pico Bolivar, 4,978 meters tall. It took work to figure out how to safely climb that mountain. But eventually, as you trained and reached those heights and helped others in the guild do the same, it became easier.
Then you discovered Jengish Chokusu, 7,439 meters tall. That's your heroic tank raid. Another beast that took you and your guild to a whole new level to be able to conquer it and do so on a weekly basis.
Just because we're now finding Mount Everest doesn't mean that those guilds just now conquering Pico Bolivar will have any less of a challenge topping Jengish Chokusu. If they somehow managed to get a Commander Luke, they may have a head start on certain parts, but it'll still be a mountain for them to climb.