I took a look through the patch notes before making the thread and didn't see anything else.
With the exception of ARR, x.3 MSQs are supposed to be the finale of the story set up in x.2 and sometimes x.1. EW's patch quests are taking a different structure than patch quests usually do, but I don't feel like that excuses how irrelevant 6.3's MSQ really was. You can sum up the entire patch with the sentence "The fiends are dead, Golbez is on his shard's moon, and Zero is nice now."
The 'standard' boss music fits the first two bosses well, not so much Halone, and in my opinion wasn't really anything to write home about. It was ok, not bad, not great. Menphina's theme wasn't to my liking, but that's probably not a popular opinion.
For the mechanics, only the second boss really had anything that stood out. Nophica had the Chariots/Dynamos that we've seen a hundred times, and both Halone and Menphina overused half-room cleaves. Nothing outside of that second fight really was that unique. I guess maybe the blue/yellow flower circles in Nophica were alright?
I feel like Aglaia just did a better job in most, if not all, regards.
This is all content that isn't available yet. For the relics and the deep dungeon, as I asked in the OP, is that content going to be worth the wait? I seem to remember a lot of hype around V/C dungeons and those were practically DOA. Both the relics and the deep dungeon have big shoes to fill, and I'm not convinced that they're going to be able to fill them, especially if the deep dungeon is just a copy paste of PotD with a couple new items. As for the Loporrits, that's just another daily chore to add to the pile. Beast tribes have never been engaging content, just a thing to log in every day to do.
And another question. If 6.35 is another failure of a patch, am I going to once again be told to "just wait until next patch"? It seems like every time a patch fails to have lasting content, I'm told to just wait until the next one, but when the next one has the same issue, I'm once again told to wait. When does it hit the point where we can recognize that this isn't a one off issue?
If the solution to the issue is being forced to take a break for months due to lack of content, that seems like a terrible business model for an MMO.
Why should you have to wait to get the rest of the patch that should already be released? The answer is you shouldn't, and said patch should have content that can last the rest of the patch cycle on it's own merit, not by artificially stretching it out by delaying it. Either that or if the content of said patch doesn't last four months, maybe the patch cycle needs to be shorter.