You have plenty of time to pull this pan out of the fire. Please consider the following:
A) Integrate the egg token seasonal boost branch with the new timers missions. Do not force players to choose one or the other, or force them to spend significant sigils to get both each season. Call it Zeppelin boost branch or whatever and have it boost both types of missions.
B) Leave the current plan in place for players to choose to complete a egg token mission or a timer mission. I’ll explain why below.
C) Reduce the number of rubies required to finish the mission cool down significantly By at LEAST 50% or more. Year of the Player and all.
This is a win/win for everyone. It minimizes the amount of work PG has to complete to roll out the feature. It preserves player choice, egg tokens or timers. It shows that you CARE and factor player sentiment into your decisions. Cutting ruby cost for pure grinding forces players into the game more often and longer. Your profit loss should be acceptable given the return on investment.