If the Swiss vote NO, then the ball is in the EU's court. The EU can accept a democratic verdict. Or the EU may retaliate and cancel the bilateral agreements with Switzerland.

A NO vote would improve the status here of Americans, Canadians, Australians, etc. They will be on par with the EU citizens for permits in Swtzerland. Right now, non-EU citizens are second class.

Meanwhile in the UK, there are strikes against Italian and Portuguese workers! In tough times, xenophobia flourishes.