You seem to be right, it is present in https://www.wanikani.com/level/6. It isn't in https://www.wanikani.com/level/16. I'll propose an edit to JMdict.
Ok it's not even done by jmdict. I didn't know. Guess I'll send an email to jisho.org@gmail.com.
It's not unusual for WK to move things around. I assume the list comes from the original order upon implementation and then never got updated.
It's always going to be a hassle update, so updating them every time something changes is probably not feasible for someone who does this as a hobby. Not sure what the best solution is.
Yeah it's apparently manual, see the post by Kim here: https://jisho.org/forum/620e27d0d5dda77afb000000-wrong-wanikani-level
WaniKani Level
This word is WaniKani Level 6, not 16.