Presumably the organisation will have to find out how many points (say) a nursing assistant needs. Then ask the applicants may have to prove they meet the points criteria(yet to be decided) i.e provide documentation, go for exams etc. Then the employer will have to show proof of role. Presumably then the organisation would be required to send that to the government, wait for approval, then wait for visa/work permit to be issues* - that will take a while, longer than it does now - this may not be worthwhile to home, business or building site. Ultimately they might pull the whole thing. If you need 20 people, only 10 are from the UK and you have to apply for 20 visas they might just forget the whole project
As far as the employee goes, they might not bother. Why when they can go somewhere else without such administration before they have even left their front door
One of the sells to Leave was lest red tape and bureaucracy