Actually, I didn't know about the Festival of Brexit until you mentioned it, and after a bit of googling, I see that's been bought up in various news article these few days.
The 68m visitors target seems a bit daft, that's literally every single person in UK being involved. I know we alone had around 200k, so I guess we'll get to hear more about it when the audit is finished.
I think they were a bit embarrassed by it so they kept quiet. At least you got some benefit. You may guess that I am not a fan of the whole Brexit fiasco.
You're not alone there.