It depends on what's being compared. Anything that has a known negative effect that is intentionally suppressed in order to maximize profits all fall into the same category to me regardless of that the "it" actually is. At the same time, we have plenty of historical evidence where a new thing was thought to be the greatest thing since sliced bread and rushed to market only to be found that it is pretty nasty stuff. We can now test the new thing much more rigorously if only someone wants to spend the money and possible delay in profits which is no company ever.

I’m more wondering about the nanotextured steel.

You're right to be concerned. Material innovators should be open about these things.

Copper is toxic, but at these levels shouldnt be a concern.

Nano stuff are nasty, but since copper in the body cannot last long (corrosive environment), the nano particles will quickly disappear.

This is likely to be far more benign than other nano materials.

The question is, will this survive outside a lab?

Copper is not safe, which is kind of the point.

That safety record says that copper dust/particles are definitely toxic to humans and there are plenty of instances of it getting into things it should not so I'm not sure what you are trying to say.

If copper found its way into everything as invidiously as pfas has, that would be really bad

The safety record says elemental copper dust is an irritant outside very large doses and acute toxicity happens at levels above a gram.

Copper is already everywhere at levels far, far above PFAS. It is found naturally in all plants and animals and it has been used for everything from coinage to water pipes for upwards of six millennia.