Now that kaido is dead yamato will not be forced to use kaido's fighting style anymore, she admires oden, want to be him and despise his violent father's nature after all, I think that she will learn it from the red scabbards to also in a way deny her oni's blood.
For momonosuke, oda introduces the nidai kitetsu for this reason imo, that's why zoro (oda) didn't trade the sandai for the nidai, the nidai was simply meant for momonosuke !

For momonosuke, oda introduces the nidai kitetsu for this reason imo, that's why zoro (oda) didn't trade the sandai for the nidai, the nidai was simply meant for momonosuke !