I assume Anna and Hachi are still going to get together unless he is abandoning her and planing on writing someone else as Hachi's "True" fated princess or make some bs about how, you have to decided your own fate even in love, to justify another girl. This is a desperate attempt to save Samurai 8 by adding spice to the story through romantic conflict. Its just, he doesn't know how to do it because he doesn't know why Naruto was a success.
You said Kishi was being tepid with it, and he was, but the thing is that that would have made it even better. It was (or seemed to be) BUILDING to something. And it could have been completely devastating. In a good way. Like with how the anime constantly inundates the viewer with sentimental flashbacks. There would have actually been LICENSE to do that. It would have been EARNED. And if he clearly locked it in before that, the effect would not have been the same.
Instead he made the resolution to his 15 years of work tepid instead. Just flat. You feel nothing. And the war arc was so tedious and boring. And the reader gets NOTHING for it.
It wasn't even rushed like Bleach. He just gave up at the last hurdle.
And if he really expected the Japanese fanbase to buy into his next manga, then I'm concerned for his sanity.
As I said above, he doesn't get why or what made Naruto successful. So, he doesn't know how to make Samurai 8 successful other then to just do his own thing, hope it works, and scramble when that doesn't work.