Don't know how to help you, never had this problem.
I ALWAYS set the hand brake before placing the shift lever in park, just to avoid additional stress on the parking pawl.
You've got the linkage disconnected at the tranny and you still cannot move the lever, correct? Have you tried to move the shift arm where the linkage connects near he firewall (kind of under/beside the brake booster). It's possible I guess that the car did try to move and there was enough strain against the parking pawl that it pulled the linkage into a jammed situation. Have any tremmors lately? Last little quake we had caused one of my cars to work it's way out into the street.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.