It seems the DD is implying that the next expansion and or dlc would be RPG element focus. And given the recent DDs that talk about events and what not, it seems they are going for a "sometimes it'll fire, so when it doesn't it'll create different stories" type of affair. Whereas Shattered Retreat and Threat was more about "it's always going to happen, irregardless".
Personally, I would have preferred a Threat relationship like the Opinion relationship, since it would make more sense for dynasties to feel threatened by you attacking their family members and in laws, than for national leaders to fear some foreign barbarian conquering some steppes. There's no particular reason that the foundation of the bonsai tree, needs to be purely gameplay mechanic based. Integrating it into old gameplay mechanics allows rpg features to better relate to it, vs introducing new mechanics which aren't supported by the previous role plays.
Personally, I would have preferred a Threat relationship like the Opinion relationship, since it would make more sense for dynasties to feel threatened by you attacking their family members and in laws, than for national leaders to fear some foreign barbarian conquering some steppes. There's no particular reason that the foundation of the bonsai tree, needs to be purely gameplay mechanic based. Integrating it into old gameplay mechanics allows rpg features to better relate to it, vs introducing new mechanics which aren't supported by the previous role plays.