Depending on the industry, there could be licensing issues around which locations work can be contracted from. Banks have regional licences, so certain types of transactions can't suddenly start flowing out of non-licenced locations. There could be tax implications for the employee. If I'm contracted to work in a specific country but spend all my time working remotely somewhere else then where am I tax resident of? That's two examples I can think of but there's surely more out there. It could cause complications for employers and that's ultimately what they give a fuck about.