The game has had a ton of full skill reworks since the launch build, mostly improvements however i do lament some of the skills we've lost in the process.
At some point after the game released all the hongmoon skills, they did away with the original skill system which allowed the most extensive individual skill by skill customisation and replaced it with two elemental specialisations for each class. Kfm in this case was split into wind and fire and each spec had their own rotations and mechanics to keep track of.
Skills in general were segregated between the two specs and neither really had access to the full skill package that you could have before.
The game progressed, new content was released and the devs kept changing up class mechanics and skills throughout the games life to better suit the new type of encounters and raids they kept building.
As a fun example, since you mentioned it, at one point grapple skills could be specialised to "restrain" the target allowing other players to unleash otherwise unavailable very powerful skills against them. The meta was pretty much, if possible, cc a boss > restrain > beat down by the rest of the grp, fun times. The devs toyed around with the idea a bit but ultimately decided against keeping it.
Anywho, skills come and go, sometimes they get changed a bit for flavor, for example the the dragon fist kfm spec has firestorm kick instead of triple kick just as a fire themed version of the original, a remnant of the old dual element skill system.
That said, our current skill patch isn't fully fleshed out yet, each class is getting a 3rd new specializatio, as a kfm you can unlock yours already, the 'iron claw' spec by completing a high level quest.
You currently have a choice of 3 ways to spec 5 different talents for each spec. Each of these talents you pick have a very broad scope in the changes they can bring to your playstyle often affecting multiple skill interactions effects and even changing what skills you have available.
tldr:
a lot's changed and a lot more's going to change
change your spec and talents around to see what skills you actually have available because skills're often hidden behind different talents