Actually, I can think of two things that would have been 'fair' to everyone.
1. Change the daily prize and otherwise do nothing. If people won a lot then that's the way it goes. No one was refunded the eggs that they used, some of which were purchased with diamonds, when the prices of the treasure chests were lowered. They came out on the short end of that change and then they and/or others came out on the plus size of this one.
2. Reset EVERYTHING to the way it was 1 minute before midnight; all eggs gained or spent, all prizes gained. Everyone starts fresh as if it didn't happen.
As things are, the people who opened hundreds of chests still have all the prizes that they won. Even if they don't get to spend another egg they are hugely ahead. Others, who opened a few chests and wanted to save the eggs for later daily prizes get little or nothing and some are worse off than they were when the day started. No way is that FAIR.