I really think this extended cut will improve the film overall, as long as the footage is of the same quality as the original it really needs that longer ninja fight to help the pacing of the third act, it really was my biggest dissapointment as its an iconic part of the comic but it was over way too fast and you could tell it had been heavily edited but it sounds like theres good chance we get a lot of that back so I think thats a big plus.
Watching back the trailers and featurettes there is several pieces removed from the cinematic version other than the ninja fight which I dont remember in the film unless I missed them
-Ninja's bowing to Mariko to pledge alliegence to her
-Yukio fighting at the funeral knocking a gun out of yakuza hand
-Some more shots of Yakuza running through the streets after the funeral fight
-A shot of traditional SS amror at the funeral (I remember Yukio talking about this but not sure if it was in the film or not??)
Whether we will get all of these in the final cut remains to be seen of course, the ninja fight is the biggest one and would help the third act I believe.
Cant wait for it to be honest!! Sounds like a strong chance of it happening