It is really inconvenient to write "2024 *purple/red/blue*" to sell the current eggs. If we only write *purple/red/blue*" we only see the ones available from 2023.
Many people from my guild were confused at the beginning and were under selling their eggs.
Make them last 300 days to avoid those guys that are taking advantage of these confusions in the future. We still get a lot of value by opening them after the event.