Around 40% of Monarchs work is still in charter work and l guess will still continue for many years to come, think about what the B787s are for, when they turn up some time in the next decade.
On the Cosmos front, if you Google you will end up at Monarch Holidays, but if you put into your browser "cosmos-holidays" you will still get Cosmos.
So it is a branding issue to sell more Cosmos holidays and link every thing to the group and make it easy for Joe public.