That was definitely my sense, starting about the second mention of Mark having A Talk with the-count-their-father about....things. That one event has been hanging over the books since Shards, because it takes us full cycle through Barayaran male adulthood. We meet Aral about to find love and family, we hear bits about his crazy hot headed youth, we get to see Miles have crazy hot headed youth & cycle right on back to mature adulthood. We know what Miles's maturity will look like as Count because we've seen it on the sidelines, for certain she won't write that story again, you know?

It's certainly a well made stopping point if she feels there's no more Miles in her. Though considering her Miles book patterns, they've fairly closely paralleled her own life stages. She may find there's a whole book about, for example, Cordelia's next life on Beta, Ecaterin's life as Countess & mother after Miles's death and Laisa's life as empress with a brain. That would certainly make a fantastic addition to the series, giving us POV from the women, from 2 other cultures & from later in life (which, frankly, is anything but boring!). I'm not holding my breath though :(

The fanfic possibilities, however, are endless and wealthy :D