I for the life of me, cannot find any links to those proposals or a good map - do you have one?
They aren't recent proposals, but here's one from 1958:
http://www.chicago-l.org/plans/NewHorizons1958.html
Here's reference to one from 1973 of a plan for service by 1995:
http://www.chicago-l.org/plans/1995plan.html
...and I found this reference from 1923:
http://www.chicago-l.org/plans/1923plan.html While it doesn't reference "Midway Airport" (which didn't even exist back then, as Chicago Municipal Airport opened in 1927), it mentions an elevated line to Austin Avenue connecting to the 63rd Englewood line, so it would have effectively gone past the airport property (and it's anyone's guess if the terminal would have been built closer to 63rd if such a line had existed back then).