There are 120 employees total and you're only accounting for salary paid directly to employees (good rule of thumb is employer pays an additional 25-40% of your actual salary in employer taxes/expenses).
Under your scenario (assuming the 120 employees figure from the article is correct) a jump in average salary from $48k to $70k minus the CEO's old salary results in a net increase of $1.7mm (or about 75-80% of this year's profits as the article stated).
This scenario isn't correct though, because an average salary of $70k means there are still a significant number of employees still making below $70k. A more realistic estimate is the average salary will be well north of $70k, and if we include the additional cost of payroll taxes (let's say very conservatively 10%), then we're talking about:
($80k new avg - $48k old avg) * additional 10% payroll taxes * 120 employees = ~$4.2 million in additional wages
Granted, that's over 3 years, but this is a very conservative estimate assuming 10% payroll taxes, no additional employees hired, and the new average wage will be $80k which is also very conservative.