Does anyone use a copay assistance/accumulator like SaveOnSP for specialty drugs?

My ENT prescribed Dupixent for some recurrent issues I'm having. It's a very expensive drug, but I have teacher health insurance and figured it would be covered.

ACCREDO (a specialty pharmacy) called me a little bit ago to tell me that they had to reject my prescription for Dupixent because I had to enroll in SaveOnSP first. They gave me the number to enroll.

I call the number and the lady on the line tells me that SaveOnSP is a copay assistance program offered through my health insurance company for specialty prescriptions that have a high cost. She goes through some details on how much the drug is and it's something like $1000/month unless I use a copay assistance program. She said their job is to monitor my prescription costs and asks if I give consent for them to do so. There's no cost to enroll and she said my cost for the medicine will be $0/month.

I asked her what happens if I don't enroll, and she said my prescription will be denied unless I agree to pay the full amount without insurance.

So I enrolled. Because...well the pharmacy said they were rejecting the script, right?

But what the hell is SaveOnSP? Why are they being sued by Johnson & Johnson for scamming drug manufacturers? Why is their website practically bare of any real information about their company?

Feels scammy. Not much info out there, but apparently people with specialty prescriptions use them.