I can't say I really get into hand-wringing over colonialism or whatnot in an escapist film of this kind. But I know not everyone thinks that way, and that could well date the film in some people's minds, as you say.

I'm not sure it's the case with the Indiana Jones films though. The Holy Grail remains uncaptured, the Sankara Stone goes back to the village, and the Ark of the Covenant... Well, there was no Israel for it to go back to in 1936, but given the divine power of the Ark, it's in a slightly different category in any case. One day when I was thinking much too deeply about the film, I theorised that the Americans used it in the Manhattan Project, kind of reverse-engineering the wrath of God. But I doubt Spielberg, Lucas, et al were thinking that deeply when they made the film.