“Brexit could well be a factor in people’s decision to move to or from the UK, but people’s decision to migrate is complicated and can be influenced by lots of different reasons.”
From the Stats comment, the UK does not collect the data to draw the conclusion however…
Closing of EU offices, loss of research, documented cases of harassment and plenty of anecdotal evidence of people leaving due to uncertainty.
It’s impossible to understand why people didn’t come via surveys and research as you didn’t know who was thinking about it, however we can look at the events and current political climate and make a resonable guess as to the factors involved.
Would you move to a country for shakey job prospects and limited support?