This is entirely a matter of opinion, but I think that a modern audience, though perhaps desensitized, might still be equally offended by Swift's work, but probably will not be.
In Swift's time, his intended audience was the British public; this is certainly a different audience than, say, the Chinese audience of that time, or the American one of today. There is a lot to be said for subjectivity when it comes to how your audience will receive you. However, dispensing with these conditions, and assuming that we're talking about the "average" audience of intent, there is a good chance that Swift will not be so offensive today. Consider the fact that we are now immersed in a culture of unsubstantiated, anonymous opinions, where people can, for the most part, say whatever they want, whenever they want; we are no longer limited to pub houses or a printing press to make our opinions a national talking point. In the modern lexicon, Swift might be considered a "troll". The fact that we even had to come up with a word to describe people who intentionally instigate arguments for no purpose other than the satisfaction of an emotional response says a lot for our maturity as a culture.
Consider, also, that most people today have been exposed to a wider variety of written material, as well as a wider variety of opinions, such that it seems more likely (to me) that Swift's work would be recognized as satire. This saps much of the shock value that it relied upon.
I think the people most likely, in a modern audience, to be offended by Swift's work would be those who consider themselves "social activists", or some similar sobriquet, who are concerned with how society acts and represents itself. "A Modest Proposal" might thus be charged as a flagrant example of white privilege, patriarchal hegemony, etc., essentially offensive, but not for the reasons that the author intended. I could imagine someone writing a response along the lines of "A Modest Proposal is just an example of how blind the author is to his own privilege. Poverty is not a joke."