Brexit has always sounded like something I'd tip into a bowl in the morning and cover with milk.
Somebody somewhere invented this verbal mash-up, and because BBC News had nothing better to report on at Christmas 2016, turns out it actually dates from 2012:
https://www.bbc.co.uk/news/uk-politics-37896977
I recall Brexit was initially a tabloid term, a snappy sort of thing you’d expect to see on the front of The Sun, and the BBC News wouldnt use it in its graphics. Eventually they realised it had gone mainstream so started doing so.
I walked past one of these posters on the way to work a few weeks ago, and wondered at the time what would happen if and when Brexit was delayed. I *think* though the version I saw was on one of those digital bus stop ad screens so they'll have been able to skirt around the issue, but can imagine there were plenty of physical posters put up too that were either hastily replaced, or more likely just left in situ until the next time they were due to be updated.
The ones on the bus stops near me were all quickly taken down.
Are you sure they just hadn’t reached the end of the time they’d paid for, Outdoor adverts do tend to be changed quite regularly, and wouldn’t be expected to stay up for a long period or even up to the 29th.