Brexit
Winger
You don't get it do you ?
Brits will not have the automatic right to work or live in European countries, the same will be true for Europeans living in Britain. No one (apart from loony right wingers) is talking of people being sent back anywhere. What will happen though is that a lot of Brits will return as the red tape and hassle of living and working in Europe will not be worth the hassle. Also a lot of Europeans will leave Britain for the same reasons plus they will likely not want to live in a country which is showing hostility towards foreigners.
Think for a minute about the demographics of who will be leaving and who will be returning.
I do get it. I just totally disagree with you and think your reasoning is fundamentally flawed.