I am also +1 to a few points along the way here.
Like the idea of Strongholds, am not particularly enthused about them bring three new slots in the next few years, and that the slots mostly make boxes on the party card larger, either directly, or by expanding slots.
I do like the concept of the follower who grows with each level or stronghold. I forget if it was mentioned here or elsewhere, but theme and story wise, it makes a max sized max power party 10 players plus 10 followers, instead of 10 players plus 30 60 followers.
I’m OK with the concept of Mythic tokens, and it being expensive to get them. I would hope that Legendaries they in concept replace are part of the recipes for them.
I’m not sure if I’m OK with 6th level being Mythic only. I would hope there are several paths there, even if the Mythic path is the most straightforward.
True Dungeon, and other games that it shares a limited resource model with, always risk turning off the next generation if the end goals seem to far. It felt very far when I started in 2015, and my token purchases were slow but steady for several years. Lots more opportunities to play with VTD changed that. I think lofty end goals can be a good idea, but the steps in between need to be achievable as well, and then in a few years, a new generation will be ready to take more steps as TD becomes a thing they do more and more, instead of a one off they maybe do once at one big Con. And then another generation after that.