We can take this as early confirmation that Switch accomplishes the sweep in 2019 because a December win is a given. Such a sweep hasn't happened often, so it's something special.
Not often is there such a big gap between platform releases. Usually consoles in the same gen are released the most one year (2 tops) apart from each other. Switch was over 3 years after the PS4 and Xbox One and just under 3 years before PS5 and Xbox Series X.