I mean, FL was a joke before, too. Melee was very overpowered and you pretty much just spammed a ton of DRGs in every team if you wanted to win a lot of games. They could toss spears at people for more damage than other melees got at the end of their 3-step combo, and it was every GCD instead of every 3rd GCD. Add the melee DR to what was basically a half-ranged class and ta-da, you have a meta monster.
We'll see this *exact same thing* happen to NIN if it gets treated like all the other melees and gets some huge DR buff. A class that's halfway to being a ranged class, but with the base HP and global DR of a "true" melee class like MNK? Yeah no shit it'll be broken. I also wouldn't put it past them to repeat the past mistake... I don't think FL really gets their biggest and best minds. And, really though, should it? If you try to get people to take it seriously, you get no end of "lol idc it's pvp" type responses and people act like you grew a third ear for thinking that everyone should be playing to win in the team game. Personally, I wouldn't blame them for not wanting to waste valuable work hours on it when over 80% of people participating in it aren't even competent enough to have a valid opinion on the state of it as it is.
Hell, people used to whine that ranged were OP in 5.x FL, when the exact opposite was true. People don't put effort into learning how to properly do anything, SE doesn't even pretend to try and teach them or provide effective tools for teaching, and most people go in and die a few times and decide "I played okay, those things that killed me are OP and need nerfed!"
MNK being able to instagib casters and ranged (and even tanks if they can guarantee a follow-up GCD before they can heal - you just delay the stun until after the ult instead of before and it works most of the time since Purify takes too long to trigger) is a *huge* balance problem in CC. I'm actually surprised we don't see more bitching about that here... maybe other DCs don't have a lot of good MNK mains? It's not surprising that it would exist in FL as well. But MNK is kind of garbage outside of that one trick they can do... I'd rather just put a pair of WHMs together, two lasers into two miserys will gib just about anything, and being able to chain two sheeps back to back is pretty strong. Or, as the video shows... two snipes landing at the same time is also pretty effective :P