Question about event buildings from previous years

A clan mate is in the same era as me, but his city is much better established than mine. While I barely manage to earn 500k gold a day and currently have 2.3M, he has 8.7G in gold and 9.6G in supplies.

I noticed that he has these buildings in each of his cities:

4 Regal Squirrel Hall, 4 Eco Nexus, 1 Forest Sentinel, 1 Mercantile Passage, 2 Urban Metro Plaza, 2 Arcadian Windmill and 3 Crimson Dragon

Is there an event coming up that will bring these buildings back?