> First, the price of a 6.5 fl. oz. bottle of Coca-Cola was set at 5¢ in the 1880s and remained 5¢ through the 1890s, the 1900s, the 1910s, the 1920s … all the way until the 1950s when the price was finally raised.

No, that's explicitly mentioned in the story:

> And thereafter the real Coca-Cola company did lose half its trademark and did grant perpetual bottling franchises at fixed syrup prices. And some of the bottlers were not very effective and couldn’t easily be changed. And the real Coca-Cola company, with this system, did lose much pricing control that would have improved results, had it been retained.