I think it is a response to the thousands of requests from Brit Expats to MEPs about what will happen to them post Brexit. The problem is that quite a large number are resident in one EU country but actually work in 3 or 4 other EU countries. At present of course they don't need work permits or travel visas and no-one can tell how this trans Europe worker will be treated in future.
If a solution is not found then I suspect that many will have to return back to the U.K. as they won't meet the specifications for residency in a single country and they won't have a permanent salaried job in just that location. Most of these are people who are interim managers, project managers, project workers, construction workers, consultants, architects, infrastructure project managers and workers, IT staff and visiting lecturers and professors. It is relatively normal for instance to work as a freelancer in these positions in Belgium, Germany, Netherlands and Luxembourg all within the same year or in fact within the same month given that you can reach parts of all of these countries in less time than it takes to get from Manchester to London.