Pick older pets before newer ones

Why is the upcoming cosmetic pet the 2020 dog day when I’m positive we never had a weekend for the 2018 dog day or 2019 dog day. Shouldn’t the older ones go first?

The idea of mirroring the holidays of previous years is a good one, but it seems like it should match a previous year consistently. That would make it much more predictable and allow new players to catch up on the oldest pets they are sure not to have. So 2021-2022 would do 2018 pets and 2022-2023 would do 2019 pets.