In fairness, and at least when it comes to rhetoric, the UK has now accepted there will be costs and obligations ie we will be imposing tariffs on imports whereas a few months back we were going to go for zero tariffs. Equally the UK is still in denial about the cost of doing this and has taken no steps to adequately prepare for it. Instead we are prattling on about free ports and bridges. So in the sense of meaningful preparation or businesses being fully aware of the problems ahead you are right to say people will lose their shit when the details come out.
The other purpose of all this talk about tariffs and trade friction is get everyone increasingly hysterical and then capitulate on the key issues with the EU plus agree a proper ‘implementation period’ and then declare all the doomsayers were wrong and victory is at hand. The press will buy it, Brexiteers will buy it,
@Chippy_boy will announce he has been saying this would happen for months (with some justification) and the rest of us will be fine with it.