There are two end to the linkage:1 is the switch on top of the steering column.2 is the selector lever on the console.

The shift rod LOOKS to be disconnected from the various doo-hickey levers that attach to the transmission and console.
It appears to still be attached to the column shift lever.

The column is moveable by hand because this rod is what attaches the transmission to the lever that move the switch that is on top of the steering column that is used various backup functions.
Similarly the Trans Selector lever move freely because it is no longer having to drive the column shift lever clap-trap I just described.
see page 146 thru 148 in the http://thefirstgensite.com/library/69assy/69-FirebirdPIM.pdf

I have done this a few times be very careful that you do not inadvertently misalign the the selector with what the column switch is set for e.g. make sure rev and the console selector align to the backup position of the column switch.

The PIM has adjustment procedure that I did not use and that was a BIG mistake