All Over world Occurrences are less frequent.

All Over World occurrences are less frequent such as I create a new world in 1.15.2 there are pumpkins, ship wrecks and underwater ruins around ... Then the same world in 20w17a The pumpkins shipwrecks  and ruins are not there anymore. I understand that the nether ruins were spawning at a higher frequency then intended but Is this intended or is all over world structures/ random occurrences decreased? 

Just thought I would bring this up just in case this was unintended behavior of the update.