Hi canjos - I am almost certainly wrong so Alex or Frank will correct me later is my guess.
Anyway, my impression is that these things can not be boiled down to one dark agenda or very much simplified without also losing other aspects of the situations. My personal guess would be that brexit or no brexit is several different dark factions trying to outsmart / outwrestle each other a come out on top.
You likely already read Franks posts on dark spheres which give a good picture on how darks view this planed and it's 'resources' that they have been trying to try to divide and conquer between themselves... I think brexit would fit into some of the more important of those spheres. Seeing London is an important financial center - probably part of financial sphere-rule?
Also, part of the ongoing war between darks - there was previous attacks by US/financial system centered darks on Europe-centered darks/vatican (LSA2 attack on LSA1? Can't remember.) Brexit sounds like it could maybe be part of that ongoing conflict?
But I should really stop commenting on these things that i do not really know facts about.