This is, I'm willing to bet, not the first guest to have passed out, at least temporarily, on Stardust Racers, and certainly not the first guest to have passed out while in this style seat and restraint system on Mack's other coasters. You excluded the part about the guest being a paraplegic with an existing spinal condition, the second of which means that under the stated ride restrictions, he shouldn't have ridden. Both of which potentially caused his body to ragdoll harder than a normal body would.
Saying "it needs a comfort collar" is a knee-jerk reaction without really considering how muddy this gets when we consider the sheer number of roller coasters that also throw guests around and have only a lap bar. What about every wooden coaster that's been operating for decades with just a buzzbar? Nothing on those would prevent a very limp body from smacking the metal or seatbacks in front of them, either. What about Velocicoaster? What about every RMC?
You are coming after me for delivering what is going on.
Most buzzbar rollercoasters you are mentioning are not at major parks. What is acceptable at smaller regional parks is much different, and never had an incident, does not mean could not happen. Often times there area indeed deaths of buzz bar incidents. Look them up. They are there. Often pre internet reporting and non on the scale of something as EPIC Universe opening. There is a reason those have become more rare and let's not kid ourselves that The Phoenix at Knoebles, a great coaster is not the same as whipping laterals or sudden shifts as Stardust Racers or Velocicoaster. Intimin is also a terrible comparison as previously, Intimin has had deaths with body types(not just the missing limb incident either) and an executive company made a terrible excuse that some such incidents will be acceptable due to America's ADA. Disgusting.
The cause of death was listed as blunt force trauma, and that is what it is going off as investigation continues to show that the ride did not malfunction, yet blunt force trauma was the cause.
You may see it as a knee-jerk reaction. But alterations are going to be done to this regardless to ensure there is a much less likely chance of it ever happening again, as just one time, is going to not only be terrible PR, but unacceptable.
If this was even close to "The rider should not have ridden" situation or a natural cause, the medical examainer's expertise would be questioned and investigation would have a better answer.
Human bodies are a huge spectrum of fit and health where generally, the restraint system should not allow anyone to ragdoll. All unconscious people ragdoll.
Thus why Stardust is still closed and will be. Also why the Peacock special was delayed again out of taste and changes and avoiding anything incriminating(not likely, but nothing is taken to chance)
While there was no malice and legally, the death is deemed an accident, there is some oversight culpability here.
Changes are coming. You don't have to like it. But it is the right thing to do.