> you own nothing
> the company owns everything
> you have no rights
> you promise not to try and exercise any right you think you have
> you agree to binding arbitration with the firm we pay, just in case you ever get it in your silly little head that you do have rights
> you cannot do anything the company doesn't like
> the company can do anything it wants whether you like it or not
> the company is not responsible for anything ever
> the company makes absolutely no guarantees about anything
> however you are liable for everything that you do that we do not approve of
That's what happens when you can alienate people from their rights via contract: alienation turns into legal boilerplate present in every single one of those documents. The only possible reason for a company not to do this is ignorance or legal liability.
Contracts that enforce only one position are not good - this is why we have string labour laws. A contract in France cannot have anything that is outside the labour law. They are completely generic.
My country's laws work the same way as what you described. I've had lawyers straight up laugh when I presented them some of these abusive contracts. This "waive your rights" business seems to be an american thing.
What I suggested is to have another company take the burden of the training that happened right before someone left.