I don't like Nvidia's approach for other reasons (mostly 'cause market segmentation raises prices in the end imo). But I'm pretty sure miners very price oriented. They'd sell rather than trash whatever cards they have. And it seems unlikely they'd be using any unsellable cards since those are energy inefficient.

There's a shortage of Nvidia card/chips after all.

Edit: Now I read the article, this is literally only being added to new cards and with a warning.