Oh come now Chromolume, don't be ridiculous. You know very very well that the "primarily pop" sound of the score in 1973/74 is not at all the pop sound of the 2000s they were forcing onto the score.
Updated "covers" have pretty much always been a part of pop music. And pop styles go out of fashion as quickly as they come in. So yes, the pop sound of the revival is very different than the pop sound of the original score. But that's par for the course in pop music, and we should really expect that more often from pop-driven Broadway scores as well. I don't hear anything that I feel is being "forced on" the score. You may not feel comfortable with the newer style, so be it, but speaking as a musician, I saw no problem with what was updated and how. The songs still work. It may not supplant the original score, but I don't feel that it's disrespectful either. (I also assume that even if Schwartz himself didn't have a huge hand in shaping the new sound, he certainly gave it his blessing. If the composer is happy with it, who are we to say that something was "forced" on the score that shouldn't have been? They're his songs, after all...)
Unless one wants to argue that Pippin is inextricably tied to its 1970's "me generation" zeitgeist, and should always sound like that era. But I doubt that's your argument, and I wouldn't tend to agree with that idea either.