As a society, we have to decide that certain kinds of voluntary agreements are too exploitative, have too big of a power differential, to be compatible with liberty and therefore are not permissible. Selling yourself into literal slavery comes to mind, but the bar can be a lot higher than that. Part of making sure that "better offers" exist is banning intolerable offers. If this damages or bankrupts your business, it means you weren't producing enough value for the resources, including humans' finite lifetimes, that you were consuming.

In this particular case, the important thing to me is the focus on honesty about the nature of the job. If they tell you, while you're voluntarily entering an agreement, that you'll have a certain degree of flexibility, and in practice they try not to let you have that, you've been lured into the deal on false premises. Usually we call that fraud, and in any case it should be uncontroversial that it's immoral.

After reading the comments here I was prepared to be disappointed by the policy direction, but instead I'm only disappointed I didn't see any specific enforcement teeth mentioned. Demanding transparency and that companies treat their contractors as contractors is IMO the correct direction; it's certainly better than retroactively classifying as employees people who never wanted to be such, as we sometimes see.