Supercell is changing the way clan chests work. We’ll have a chance to open a clan chest every week! They’ve roughly halved the number of crowns required to open the highest level chest but they’ve also reduced the number of days to 3. The rewards are a little better but a closer look at the numbers reveals that the change is a net loss for players. 

The old Clan Chest allowed us 7 days to collect 3250 crowns and unlock the highest level chest.

The new Clan Chest allows us 3 days to collect 1600 crowns and unlock the highest level chest.

So, the old chest required us to collect 464 crowns per day and the new chest requires us to collect 533 crowns per day. This is a 15% increase.

The old clan chest gave us 525 cards and 3150 gold. The new clan chest gives us 540 cards and 3240 gold. That is less than a 3% increase.

TLDR; The increased input doesn’t match the increased output with the new Clan Chests.

Sources:
Clash Royale Forums: Maintenance Break: New Clan Chest & Bug Fixes
Reddit: New Clan Chests!