Yes, I agree sometimes the details are way, way too much like an employee-employer relationship than IC.
The big difference is I can walk away from the assignment. Just choose to not complete it.
There are hundreds of assignments available to me every month; I choose to complete anywhere from 10 to 40, depending on how many profitable "routes" I can construct.
It is that freedom I would lose if I were determined to be an employee.
I believe the rule changes that are coming are focused on protecting gig workers from being exploited. And yes, I think change IS coming. I'm just not so sure that that it will be the sweeping changes you are foreseeing, and I'm not at all sure that it will impact MSing.
MSing has been established for quite a while, long before the "gig" economy (which has been fostered most by the leaps in technology) exploded.