I understand the sentiment, too many people have this crazy idea that they might be on the upper cusp of their tax bracket and a tiny bit more income will somehow end up costing them more.

But it would be sad if the entire article is dismissed by HN readers just because they tripped on the one line you point out.

Imagine instead that the author said (and I would argue they probably meant), "push more of your income or benefits exercised into a higher tax bracket".

I think this is what most people mean since it is behind the strategy of holding on to benefits until you are retired (or in a lower tax bracket) before exercising them.