Correct. Apparently once the zones were revamped, someone thought it would be efficient to go back and delete the old versions of the zones, since ostensibly nobody would be using them anymore.
Fortunately, Highpass Hold was the only zone that got the axe before that was stopped.
In the client hard-coded list for Titanium, the original Highpass Hold is zone #5:
http://www.shendare.com/EQ/Emu/EQRI/...um_EQZones.htm
In the client hard-coded list for SoF+, the zones go from 4 (Qeynos Hills) straight to 6 (Highkeep).
http://www.shendare.com/EQ/Emu/EQRI/SoF_EQZones.htm