That is a poor comparison because its not a comparison with a single variable changed. Kraft and Heinz went from two independent companies to a single one controlled by new ownership engaged in organization-wide cost cutting. The world also did not stand still over that time, it probably also changed in many ways.

Its probably impossibly to conclude with any confidence that the results were simply due to cuts to the ad budget, cuts to the budget and cuts to operations, or simply cuts to operations. Ads are also not commodities. An ads effectiveness is also not the result of pure spend, cheap ads can be very effective and expensive ones can also not be effective and vice versa.