I don’t understand the whole “but it will make our current gear obsolete” complaint. Isn’t a huge part of the game the process of earning better and better gear? Once people max out they tend to get bored and move on - that goes for every game I’ve ever seen.
Releasing new level caps with harder content and stronger gear keeps people engaged and playing. We’ve reached the point where more and more players are becoming able to complete boss 4 consistently, meaning it’s time for more challenges.
Orbus does a great job of making challenging content, so I’d expect that any new content would be challenging for those with full +6 gear, even requiring them to get new and higher gear (from the new content) before being able to complete some of it.
Goals are necessary for player retention. Those who quit because they no longer have the “best” gear there is, are likely not interested in actually playing the game anymore. Standing around Fellowship Court spamming spells and looking shiny isn’t playing.