If you're talking general upkeep, then of course. And additional attractions (that are actually good) would be appreciated.
Aesthetically, though, I don't know how much there is to be done in terms of modernizing without getting rid of some of the rich cultural distinctiveness that has been achieved by the pavilions opting for a more "timeless"/idealized design approach.
Put another way: 1770s Philadelphia is a more interesting framework for a theme park pavilion than a modern American city.