Cold bridging plasterboard do I need to be concerned

[aveatry]

I took down my kitchen ceiling, it has one wall that is an outside wall, mostly taken up by a window. During the process of taking down the old ceiling most of the wall plaster sand / plaster mix above the window about 10 inch has come away near the ceiling exposing the internal brick work, the wall there is an insulated cavity about 50-75mm in the brick work, 60s house but that part has been rebuilt so the cavity does have some insulation.
When re boarding do I keep the plasterboard off the internal wall by leaving a gap --- but then when the removed / fallen off sand/ plaster wall has been replaced with a bonding and finish coat am i not reconnecting the wall to the plaster board

 

[^woody^]

Wall plaster has a limited life, and yours reached it.

If there were no problems before, put it back together how it was and it will be fine for the next 70 years.