AOR Core p. 393 sidebar "Rebel Alliance Military Ranks" mentions "Light Cadet" in the Starfighter Command column.

Was this a typo and supposed to read "Flight Cadet" or is "Light Cadet" correct?

Thanks in advance!

It should be Flight Cadet.

Flight Cadet, IIRC it's actually referencing ye olde X-wing space combat simulator game where those were the ranks you could progress through.

Though if you like Light Cadet more there's nothing stopping you from using it... Seems like that would be a Rank for the Engineering Corps, ya know... "OK Kid, here's some bulbs, go change out anything in the base that's flickering or out. If ya do this job and show some real promise maybe we can get you a promotion to changing A/C air filters in a few years."

If you actually want to use it as such it could also be taken as a shorthand for the type of fighter you're trained for (interceptors rather than bombers).

Given all the random quirky lingo in Star Wars it wouldn't be out of place.