Ohio did this under Gov Celeste years ago by levying an “Exit Tax” equal to 6 months wages to “cover retraining and unemployment claims”. Many companies were leaving the Rust Belt for more business-friendly employment opportunities in the South. After about 9 months of this law, someone noticed that there were no new business formations in Ohio.
To their credit, the rescinded the law. It would appear that SF didn’t get the memo. The fact that they are even thinking about it will only serve to hasten the exit.
I have a company with 100 employees in the state. I want out but am hamstrung by this tax. 100 employees for six months is a pretty penny. So, I lay off all but, say, two employees six months before I plan to shut down operations for good. I give the notice and must pay the tax. But six months of two employees' wages is a lot less than six months wages for 100 employees. In the meantime, the 98 laid off employees are a drain on the state.