More adoption first, then the news and not the other way round.
First, global markets are all interconnected, one domino can upset the lot, look at Lehman Bros in 2008. Second bitcoin is acting as a safe haven and has been seen to go up during Cyprus bailins or China capital controls for example.
We are quite far from there, as at the moment Bitcoin is merely a speculation vehicle, that is exclusively driven by speculative pumps and dumps.
Mass adoption is still a remote dream, myself would love to see it happening, but there is still plenty to be done.
If the crash, similar or worse that the one from 2008 would happen today, only a very tiny amount of money would flow into Bitcoin. An average Joe is still very far away from putting all his savings into Bitcoin. Would you?
PS. With Brexit we are talking about an event organized entirely for the needs of the internal UK politics. It hould have no impact on Bitcoin at all.