I agree completely, plus there are a lot of other cruise lines that have the more active stuff, although there will probably be one or two active elements added since the ships will be a little bit larger, but the bulk will definitely be in adding things that everyone is capable of doing, no matter their abilities because that is what Disney does best.
Let's face it, not everyone is physically capable of using a wave pool, rock climbing wall, ropes, etc. But every can enjoy the midship detective agency (although I wish they would have brought that to the Magic and Wonder).
So I would look for more things like that to be added to the new ships.
With the newer projection mapping technologies that have been developed for the parks and maybe even further improvements, they might even find a way to bring the interactive portions of virtual portholes to real portholes and verandah doors, especially in the evening, but I think it might even be possible during the day as well.
They may also bring in virtual balconies like some other cruise lines are starting to do.
I expect that there will be three absolutely incredible ships that will be clear they are sister ships, but also each will have their own features that will make them unique, but I don't see Disney adding a ton of super active stuff that not everyone can enjoy. Yes, there will likely be some, but not a lot.