7.2.5 had the Chromie Scenario, a new Darkmoon Faire attraction, a new Pet Battle DUngeon, a huge amount of class changes and legendary changes, a big revamp to the Keystone System. And that's not even listing the less frequent stuff like new Microholidays or Timewalking.
Meanwhile 7.3.5 has a BG that we don't even know anything about (They said that 7.3.5 will have a "Preview" of it, and it will be "teased" in 7.3.5, which makes it sound like it will merely be a Brawl for a week,
it's also not part of the "What's New" tab.), a Timewalking Event which is only available every few months, and a Leveling Revamp which feels completely out of place without Allied Races and 5 new Story Quests, which are not finished.