Yes they literally did. Your article says exactly what I said:
The 91 percent bracket of 1950 only applied to households with income over $200,000 (or about $2 million in today’s dollars). Only a small number of taxpayers would have had enough income to fall into the top bracket – fewer than 10,000 households, according to an article in The Wall Street Journal. Many households in the top 1 percent in the 1950s probably did not fall into the 91 percent bracket to begin with.
You need to understand the difference between marginal tax and effective tax. What you're referring to is effective tax. The parent very explicitly said marginal tax.
[0] - https://www.cbpp.org/research/federal-tax/marginal-and-avera...