I tend to agree. An "express train" to the remote lot is not an express train compared to the Blue Line that already exists.
If the city was really serious about an O'Hare Express, they would include another 2 trackways for mainline rail in the median of I-190 when they reconstruct it in a few years. That's gotta be cheaper than a new tunnel, and you can use highway funds to pay for most of the work.
How would people feel if the Blue Line was cut back to a Miami-style intermodal center near Mannheim with an ATS transfer, and the new O'Hare Express took over the last mile of Blue Line tracks into the terminal complex?