It has always been true that businesses could avoid paying overtime by hiring more workers. Any time there is a time and a half scenario, that is true.
A business has to weigh against that the cost of hiring. But in that scenario does a current "manager" really lose? If they have a salary of, as the article posited, $23,000, and get no overtime, then if the employer has to choose between 1) keeping that person at 40 hours for that salary, plus hiring someone to do the overtime; or 2) hiring two people to do the work, evenly, for a certain hourly rate that is competitive enough to get people to show up.
The alternative is what you have now, which is using the label to falsely claim someone is a manager, and to effectively pay someone less than the hourly rate actually should be, in some cases less than minimum wage.
I have seen this scenario in a case I handled up close, and personal. It is a favorite ploy of certain Asian restaurants, where they send an employee over to the US on a work visa, call them a "manager" because 10 minutes a week they oversee the cleaning crew, and by contract they can only stay if they work there and work like 60 hours a week. Their effective hourly rate would make you embarrassed for this country!
There is far more abuse going on out there than you might realize. And I might add that the rule is just proposed. There will be hearings and input. This is the way the system is supposed to work.