Containers can mean many things, if you mean plain docker default configured containers then no, they are a packaging mechanism not safe environment by themselves.
Just because this attack example did not contain container escape exploits does not mean this is safe. Its better than nothing but nothing that will save us.
Those supply chain attacks we are seeing are bad, but if someone burns a 0day container escape for it, it would probably be a net positive effect on security overall. Just saying this is FUD.
