I don't really know about the name - I think I fall into the same demographic as people above who remember the '90s when "hurr durr" and a whack in your own chest was very clearly a disability-based insult, so as hurpdurp has been turning up again I've been automatically associating it with that. But, yeah, in current usage it does seem to mean something closer to "adorkable" than "retarded" so it's possible younger people don't have the same association?

However, when one of the most widely-distributed fanworks of her is this animation? Yeah. Somebody is definitely making the connection to intellectual disability.