The only thing more frustrating to diagnose than a circuit that fails all the time is a circuit that fails some of the time. Trying to correct the issue becomes a lot harder if you don’t have a way to reliably reproduce the problem.

With that in mind I think most of the time if a manufacturer cheaped out on making a less reliable component then the engineer designing whatever circuit it was going to be in would probably rather find a more reliable chip, create a different, more reliable alternative to the problem, and/or try to omit that feature entirely. And I think if the manufacturer started cheaping out on those chips after the fact then it would be a stain on their reputation as suppliers of no longer reliable parts.

For every few cents the manufacturer might save on lowering the quality of an existing part they’re likely going to lose many more dollars on engineers no longer trusting that manufacturer to continue to provide parts they want to trust will be good when they’re producing their second 10,000 unit batch for the same circuit, or when that engineer is 5 projects down the line and needs that chip again.