This isn't changing if it is taxed or not. It is merely about if the tax should be paid in the year the work was done, or spread over the 5 years after the work was done.
> This isn't changing if it is taxed or not.
This is untrue. The rule is not about taxation, but deductions/expenses. If your expenses cover most revenue, you owe little in taxes. With this rule, a particular type of expense (software engineering salaries) is no longer deductible from revenue to calculate taxable income over which taxes are owed. So you might previously owe no taxes, but now you do. The deduction might carry over to the next few years and eventually (after 6 years) you will reach the same point - assuming your salaries don't go up and your business doesn't grow. The remainder in deductions will be returned after the business stops employing software engineers. I'm not sure why anyone would want the tax code to incentivize a business outcome that all of us would consider failure.