its open, but will they have stuff replaced by then? depends on what your looking for, the replica statues on the nature trail, not unless they rebuild them, the underwater statues? they had 6 now they got 1. the beach is still there but for the money it's not worth it.
If you want to see reef and fish, do not go to this park, it was demolished underwater, take a snorkel boat instead to see local reef. also consider xcaret and xel-ha for good water parks.