There's a history of monarchist sympathy in Ireland, partly stemming from the history of anglo-irish wealth in Dublin (readers of this journalist's paper) but also the political party that's been in power for the past 11 years would be historically sympathetic (as I guess would some subset of their voters).
That said, none of the above is broadly representative of a majority, and apart from the one example she posts there of a tweet being shared out of context, there's been a very loud and varied anti monarchy sentiment expressed within Irish (not American) media and circles today. Much of the reportage is in fact not misinformation.