To be honest, there are lots of fine detail changes happening: rescinding of promises, “ah yes, but I obviously didn’t mean that…” etc.
And, if I may be blunt, many of those supporting Brexit aren’t the most observant or intelligent.
They won’t have noticed or appreciated the significance of the EMA leaving London, the Banking Regulator leaving, the Space Science Data Centre leaving, and now UK being told we won’t have access to the European Space Agency’s satellite cluster.
When these are all brushed under the carpet, and Vote Leave and the brexity press like the S*n and BBC delete the lies told before the referendum, or try and mansplain away “of course you were voting on Customs Union membership, but obviously not £350m per week extra for the NHS…” The brexit voters won’t notice they’ve been robbed blind by people with tax dodges to protect.
So no, there will be few regretters until the REAL problems hit us, and even then many Leave voters won’t blame the people peddling the “£350m pw” lie or the “Turkey IS joining, and we can’t stop them” lie. They’ll blame the ones who’ve always known this is a stupid idea, because “they didn’t believe enough in magic unicorns …”