alt Hacker NewsYes, and ADM-3A also had "↑" on the "K" key, because \013 is vertical tabulation (VT), and "→" on the "L" because \014 is form feed (FF). It all makes perfect sense.
If terminfo database is to be believed, quite a lot of other terminals reused this control sequences too, for some reason.
In the era when video terminals were new I have to guess that K and L were just plausibly related enough to justify using them for additional cursor motions, after H and J fit exactly.