Simply put, it's about time that Ultraman got back to its roots. It had always been a show about a human paramilitary monster-fighting team that protects the world - and has a big guy who can be called in to do the heavy lifting when all else fails.
More importantly, it was, and always has been about hope, and miracles, and doing the right thing - no matter the cost. But lately, it had gotten to be about darkness, despair, - and death. Even worse, it degenerated into endless fighting, or who was the most powerful warrior, rather than focusing on a race of protectors.
It was not an accident that the most successful Ultraman series/movies were about hope in the future, optimism, and the courage to face the Unknown, not trying to destroy it, or flee from it. And, it wasn't an accident that the Ultraman series/movies who turned away from that had the least amount of success.
Hopefully, Saga will turn that around.