I believe that in the development of 4e, the designers clearly had a vision of fantasy adventure to start with that they were interested in simulating with rules. Third Edition in its magic structure, more or less followed closely to the power progression found in the previous editions of D&D. When it comes to the power changes overall in level, I think 3e followed closely with 1e and 2e, with flight, invisibility, teleportation and similar abilities appearing roughly at the same levels where they did before. While changes in class structures, feats and skills and many other important changes in 3e made large differences in gameplay, I don't think they overall affected the implied worldview of a D&D world in the same way that, say, the existence of low level Detect Alignment spells do.
During 4e development, I think it's clear that the designers started with a vision of a world of sword and sorcery genre and then reworked the rules and specific examples to better match that. Or, at least, stretch the level zone where that kind of game is plausible out as far as possible. I suspect that Epic play will indeed involve things such as multiple flying PCs, straightforward resurrection and the frequent use of powers to avoid non-magical challenges, but I suspect the designers wanted to push that off.