From what I can tell, it seems like all of those quests where they're supposed to take you out of the map after killing the thing in the map are broken.
Brief bug summary: The Nuclear Option's explosion doesn't happen
More details: The skill is supposed to have an explosion followed by the scorched ground effect. Instead the missile fires, nothing happens for a second, and then the scorched ground shows up. There's no explosion animation and monsters don't take damage, it just fully doesn't work.
(anything not included in the other sections of your report)
Steps to reproduce: Be a Cannoneer, get the Override 5th job skill The Nuclear Option, use it
Let's be honest: a very small portion of the community really bothers for Level3 Link Skills. It's a nice bonus, yes. But on the other hand it's a pain in the ass for certain classes to bother. I can't say I would be upset or annoyed if Level 3 Link Skills would be gone, as I only have one character with that. Most other have two at max, and like said the very small minority has more than two. I can see why it might be considered to be removed because 210 is an absurd number for a fairly petty bonus in some cases.
I mean I doubt it gets changed at any time but changing the requirements from 70 - 120 - 210 to 65 - 110 -175 would make them more comfortable for the majority to get these link skills on level three. Also getting a quick answer is unlikely because speculations were made with the 25* update to be consistent with JMS' Level 2 Link Skill policy, and you see it didn't happen. We however did not get any feedback regarding these speculations so don't count to get any for your question here.
I don't really think "not a lot of people use it so we can remove it" is a good philosophy when it comes to game design. I feel like if you put in the effort to get there you should be rewarded. Granted I have a bit more investment in this since I have every lvl 3 link aside from Kaiser and Mihile, but my point stands.