It is likely, particularly given the "name recognition" of the day, that at least some of the packaging was prepared before "the ink was dry" on the deal.
When one company buys another, there are three ways things change. One way, the new owners run the old packages until the stock is gone, then switch over. Second way is run both old and new until the old is used up.
Third way, new owners are proud of their name, want it on the product from day one of ownership, and have supplies of new packaging already made up and ready for use when the deal is official. At a guess, I'd say this is what they did then.
When one company buys another, there are three ways things change. One way, the new owners run the old packages until the stock is gone, then switch over. Second way is run both old and new until the old is used up.
Third way, new owners are proud of their name, want it on the product from day one of ownership, and have supplies of new packaging already made up and ready for use when the deal is official. At a guess, I'd say this is what they did then.