I'll say this...there have always been and always WILL be budget cuts. We're maybe more aware of it now - but you can go back to the original construction of
Disneyland and find things that were cut out due to budget constraints. And it's not just at Disney.
I do believe with the nighttime shows - they realize they have to make those be top tier. I think Rivers of Light kind of opened their eyes - they wanted something there at night, but with the restrictions of the animals and such they were limited in what they could do, and the concept was maybe good but the execution a disaster. But since then, Disney has been very cautious with rolling out new things, and I'm sure they also see the fact that a not very popular nighttime show has not caused the surge in evening attendance they would've liked.
That said, I think they are aware that Illuminations is a very important part of Epcot and much beloved by many, and I think they are taking it very seriously. The fact that they are announcing this a year in advance says that they don't think this is just some "swap it out and nobody cares" project. I have confidence that they'll get it right.