A question about Cycles

I'm thinking about buying LE and giving it a go (currently a PoE Player).

My understanding is that a cycle in LE will not be restricted to new cycle characters. Meaning that if I have a fully decked out character in legacy, i can login and simply enjoy the cycle mechanics/content without having to grind a new character

Is this the correct understanding? From an outsider looking in that sounds super cool if thats true.

But if that is so, wont players be bored and leave quickly once they quickly experience the cycle mechanic and pick up some gear? In D4/PoE the journey from level 1 to 99 is baked into the "seasonal" cycle, and helps keep players engaged and goal oriented, without it I almost feel like it cuts the amount of things to do by quite a lot.

For LE veterans, am I looking at this the wrong way? Will cycles be this huge sprawling content that even keeps max level players engaged for long periods of time?