I think that a lot of people will still support Brexit. Leaving the EU allows a (future) government to do a lot of stupid things. Throwing out good fiscal policy, eroding human rights, aggressively stopping boats or changing migration rules, reversing climate change regulation. A lot of people believe, or will be led to believe (because previous governments were hamstrung by the EU), that those stupid ideas are actually quite good ideas.

Brexit was necessary for those ideas to be implemented. An individual's view on whether those ideas are good or not will correlate with their continued support of Brexit.