If the rumours are true I really don't understand the way things are going. WDW appears determined to reduce itself to place for families with little kids rather than being the vacation kingdom of the world.
Disney could introduce IPs to Epcot in a way which still supported the ideals of the park, although many people don't like pandora the PR spiel all supports the new land upholding animal kingdoms ideals so why not do this at Epcot?
There are loads of IPs which could work in future world. Obvious ones ones would be Ludwig Von Drake or Bunsen Honeydew and Beaker taking us on a map cap journey through a future world topic or maybe a ride based on the classic goofy how to series on a similar topic. Having nemo at the seas might not be the best example but you could build on this concept - there are a wide variety of nature and animal IPs to use at the land if you wanted to, dream finder and figment are crying out for a return, inside out could be a good fit for a new health pavilion maybe even combined with the incredible teaching us about the limits of the human body, or a torn based look at the internet.
Yes any park needs a good mix but there is no reason why Epcot can't modernise itself and still stay true to its values - all it takes is some creative thinking