Gorkaland and it capital Darjeeling never speaks Bengali. Indian states were divided on linguistic basic, hence gorkaland cannot be part of west bengal.
Second, Bengalis has got their own country called Bangladesh. Bengalis can go to their home country bangladesh and settle there.
Let us merge west bengal with Assam, Bihar, Orissa before bengal is islamised by Bengalis. And more importantly before communist flag of china is hoisted in west bengal, we indians need to do that.