The problem still persists. My wife, who has GE, green card & Canadian passport, cannot get through OLCI on a one-way ticket home to the US. It wants to know her address while "visiting" the US and her date of return. I reported 2 1/2 years ago that if you put in a date, it will let you continue - that was on the advice of a telephone agent - but I'm still not comfortable with that approach in that it's not 100% truthful if one does not have a date of return planned. Undoubtedly she will return to visit Canada in a few months but at a date unknown.
It is ridiculous that this has not been resolved by Delta while so-called lesser carriers such as Norwegian handle if fine (ex-UK on a one-way). Fortunately ICE has their act together and it's handled correctly at the GE kiosks so long one scans the green card and not the passport.