A suspended ceiling may be constructed using metal grid and drop in tiles.
Or it can equally be a timber or metal framed dropped ceiling boarded with plasterboard.
It's a suspended ceiling either way.
Just because we have got used to thinking of a suspended ceiling as the grid and tiles type, doesn't mean there are not other types.
The OP clearly states that it's a suspended ceiling with a double layer of plasterboard. In which case, it may or may not be designated as a fire barrier. The architect/designer should be able to confirm.