1 - Automation and/or business process improvements reduce the need for employment. These might not have made sense with cheap enough labor, but the more expensive labor is the more time, effort, and cost can be spared for such efforts.

2 - Push existing people to work harder and/or hire more qualified better workers at the higher rate to do more for the extra rate, pushing out the marginal employees.

4 - Business goes under, or location goes under, or expansion on site or to new sites, or start up of new business, or success of new business doesn't happen - Either directly because of the costs, or because they raise prices to cover the costs and sales are lower at the higher prices. No replacement here, the job is just lost.