I think there'll be a big rise in near-shore work. I've worked at companies in the past with either direct satellite offices in eastern Europe, or just simple sub-contracting to an outsource firm.

The difference between a team of 6 UK/EU devs living in London, vs. 6 EU devs remote working from Poland isn't that much. It's a little trickier to manage, but is cheaper in terms of living expenses and therefore salary.

So far from Brexit bringing back jobs to the UK, it'll just drive away anything that can be done remotely.

This means that the companies will probably still stay in London, but the jobs will go elsewhere.