Same here. The Cottage Living eggs are the ones sims find on an egg hunt now instead of the decorative/collectible ones.
If it IS by design, then AT LEAST make finding the Cottage Living eggs during an egg hunt fulfill the Egg Hunt tradition, because as of now, it does not. There's currently no way to complete an egg hunt in the game because the tradition spawns a different kind of egg than is required to complete said tradition.
At the risk of stating the obvious, if you're going to change the type of eggs that spawn during an egg hunt, then you need to change the tradition fulfillment requirements to match that type of egg. Pro tip: Find/Replace works wonders when code needs to be updated in multiple places.
Fix this please.
EDIT: Confirmed. You cannot complete an egg hunt on a lot that has a chicken coop. (#Irony) If a coop is on the lot, the game spawns chicken eggs instead of decorative ones for the egg hunt. I sent my sims to visit another household that does not have a coop, and they were able to complete the egg hunt on that lot.
Without looking at the code, I'm guessing there's nothing to distinguish between egg types as it relates to spawning on lots. Spawn eggs always equals chicken eggs if there's a coop on the lot. Tag the decorative eggs needed to complete the egg hunt tradition with an identifier, then update the eggs in egg hunt requirements to include that same identifier.