Indeed, I don't think they realized the humongous task ahead of them with trying to make all encounters more engaging when you realize how much there are. Following the trend in SHB, that's 12 dungeons and that would be 39 bosses and the respective mobs in all of them. Then we have the standard 12 raids, normal and savage. Then we have the 7 trials and then the 7 extreme trials as well. Then we have the alliance raids of 4 bosses each that's another 12 fights there too. Then we have either 1 or 2 ultimates. Then we have the miscellaneous content like variants or criterions and in that case that's another 7 fights as well at least one set, the 4 that are always in it and then the ones at the end of each path. That is a lot of encounters and they'd have to make sure that each one is fun according to their own statement.