Not the same as Chevelle. Although it would have seemed to have made sense to have had all the A body cars share the same roof skin, and rear window, along with it's channel to reduce costs. The divisional identity stuff could have been done elsewhere, as it was - with front clips, doors and rear quarters.
You might? be thinking of the Pontiac Grand Prix. 68-72 Chev. A body shared it's rear window with the G body 70-72 Monte Carlo. Believe the GP '69-70 may have also used that rear window, then changed for 71.