v-e: To be clear, I said "seen to be insular" -- perception is sometimes as important as truth. At the moment, we have seen a drop for example in applications at University from students coming from abroad, even though nothing has actually changed in practice. What's driving this, then, if not a perception that the UK is no longer so welcoming to outsiders? It will be important to show to others that that perception is wrong.
As to the predictions coming back to life in two days -- I doubt it. Things have changed in nine months, and the UK is at least in theory better-prepared to start the process -- as is the EU, for that matter. On the other hand, the other assumptions that went into the prediction may yet still have some sense to them. I'm no economist, so I can't evaluate the soundness of the models used, but there was certainly more to them than "Brexit starts on June 24th". It depends on what Brexit means to Theresa May, David Davis et al, and it depends on how the EU will respond to that, but however you look at it there's still a great deal of uncertainty ahead.
For what it's worth, though, I was never particularly interested in staying in the EU for economic reasons, and I was never especially convinced by the doomsday scenarios that some were predicting. I'm sure that Brexit *can* go wrong economically, but it seemed to me that it was in people's interests to make sure that it *didn't*. What has troubled me, though, is how people have appeared to use the predictions, and their not materialising, to essentially dismiss the value of expert opinion and advice, rather than trying to understand why the predictions haven't come true in practice. And that wasn't because they were made-up bull in every sense, but because they assumed that Cameron meant what he said before the referendum.