I think an optimistic tomorrowland is a key part of Disneyland along with nostalgia for an idillic past which never was.
We'll only get a better tomorrow if we dream it and work for it is a key message which the land should inspire.
Id love to see a really futuristic happy tomorrowland which shows what we could be if we work to it.
Rather than the whole retro thing to save long term update costs I'd love Disney to go for the future and embrace the change admitting its gonna change again. Embracing the idea that tomorrowland needs a major revamp every 15-20 years would be a great way to keep the park fresh and inspire new generations rather than thinking of the way the land dates as a problem it should be the strength of the land and the thing which makes it different from the rest of the park