Jesus Christ therefore recognizes the thief on the cross as righteous while simultaneously acknowledging the impending physical death of them both.
Jesus Christ did indeed descend into Sheol, to lead the righteous dead from captivity. This included the thief on the cross whose righteousness was acknowledged.
Jesus Christ *did* see him that day in paradise. No other elaboration or theorizing is necessary. The meaning is plain when understood in the context of the afterlife under Judaism.
Thanks, you have given me some things to think about over next few days.