Maintenance is scheduled for the 28th and they are planning a big update for December. So very likely, they are preparing for Book III.
In the meantime:
https://www.reddit.com/r/FireEmblem..._are_the_unused_skill_effect_tags_introduced/
There are some unused skill effects that were found in 2.11.0. This was how some people found Nullify Follow-up before it was released. Now the effects include:
A Stat-boost skill that also adds a guaranteed follow-up, but it deals damage to the nearest ally and can damage multiple allies if both are the same distance to the user(so if multiple allies were adjacent to the user, they all get damaged). So it's a Fury-like effect that damages allies rather than the character.
A skill that gives stat boosts and disables skills on the foe that guarantee follow-ups, much like Null Follow-up, but but rather than dealing damage, it places Debuffs on the closest ally and multiple allies if they share the same distance to the unit.
By the words Triangle, I assume that this might be for a triangle attack weapon for the Whitewing Sisters. Basically, if number of allies within the spaces are greater than whatever, it not only gives stats during combat, but the unit attacks twice like a Brave Sword effect.
So a Fury effect that nullifies Foe follow-ups if the unit initiates combat first. However, the follow-up preventer only works if the unit initiates combat while the stats and damage activate regardless of who started combat first.
Basically, some sort of skill that restores HP to an ally with the most damage.
Some sort of status effect skill.
Basically, it's a skill that's the opposite of a Chill B-skill, that instead boosts allies even more. Thankfully, it never buffs the user if they have the highest stat, but this can basically stop a Chill skill from effecting your highest stat unit or make them even more deadlier.
By the looks of it, it's some sort of upgrade to the Threaten Skills, affecting foes that are the closest to the user.
And this unknown one.
Either way, some of these skills are definitely going to be dangerous. I mean, that Fury one that damages Allies rather than the user practically helps set-up allies for Desperation shenanigans. And the Debuff ones that affect allies can be used alongside Harsh Command.