Making it illegal is the the whole point of AB5. Contractor status was once for a very specific kind of worker: independent professionals who were basically solo businesses. It has turned into a giant loophole, where worker have the downsides of employment along with the downsides of being a contractor. AB5 aims to return to the status quo, where if you want to hire a bunch of employees, you really have to treat them like employees.
They were arguably employees before (and outside of CA) and unarguably employees under AB5. That’s why Uber is making this ridiculous claim that it’s not a transportation company: otherwise, its drivers are employees.
If the law says they're employees, they're employees until the law changes. In the same vein as my earlier post, the fact that a corporation wants to "employ" (in the basic dictionary sense) workers under certain arbitrary terms doesn't make said arbitrary terms legal, nor does it create a mandate to make them legal.