Not really a myth..but also not really insurmountable.

Ramps 6, 11 and 23 work for airframes larger than a MD11, along with some (but not all) parking spots on Ramp 9. Wingspan is a limitation parking on the wings, but so is fuselage length and main deck door placement (fore or aft wing).

A 767-400 freighter would really be an ideal MD replacement, with a practically identical footprint and just 10% less cube with greater efficiency/fleet commonality...but Boeing isn't returning my calls right now.