I've only read the updates once, but my general impression is that my dragons have effectively been nerfed on a grand scale (happy to be corrected).
The new ranking system (bronze 1 to platinum 3) adds 3 new ranks above the current A+. That means the last 18 months I spent getting a wide variety of dragons to A+ has been significantly 'backstaged'. Instead of working on my lower rank dragons, I have to go back to the completed ones and continue pushing them all up 3 more ranks or they will be underpowered if used for battle. That's quite disappointing. I see they are automatically pushing your dragons to the rank that befits the number of battles they have won. That's good at least, but will benefit a handful at best. Most of my rank A+ were put aside at 250 wins so I could start the next dragon.
6* Empowering is the same. Now all my 5 star dragons are not maxed out again. This change is really annoying. It takes so long to get a dragon to 5* as it is. How many orbs is it going to take to hit 6*? It's 800 for 5*, so maybe 1000? And how long to do that empowering? I can't get through the current backlog due to the unreasonable Empower times. Now all my 5* dragons have to rejoin the list (assuming I can actually get orbs for them). I was just closing in on completing my High Voodoo. Now, I'm effectively nowhere near completion.
Although these changes might have been largely requested by the community, I feel they haven't been thought through effectively. It feels like starting again (I accept its not a total restart... something I've had to do after losing a level 80+ account previously).
Other changes are a bit 'meh'. New battle system between elements is largely irrelevant. Guardian Tower dragons as collectibles is OK, but will need to see if they are any good (compared to Ascended, Redemption, Karma, Titan, Vampire etc... if they are standard legendaries, they can't compete and therefore unlikely to be used for anything).
Happy with a new element. Not so happy they altered the ancient dragons. I've put effort into my ancient dragons as they seem largely underused and therefore gave a slight edge at times. Now, they all work like standard legendaries.
I was hoping for more dramatic changes. New towers for the islands that don't have them with useful associated boons. New mini games to freshen or replace runner and puzzle (they stopped being fun quite some time ago due to the repetitiveness... please put some effort in the events so it's not just the same thing month after month).
Most of all, I wanted an Evolution system. So many dragons with great designs get no use at all in the game, due to being Common - Epic variety. If there was a system to Evolve them into higher families (epic to Legendary, for example) it would increase the variety of dragons we come up against in PvP elements and make players collections much more diverse.
All in all, this hasn't particularly motivated or excited me to play more.