It is odd to me because in my previous experience, as I explained, I was familiar with the word ceilidh as a term to indicate an event a defining feature of which was its non-Englishness. So, to me, it comes across a bit like saying, "We're going to have an evening of Conversational French" when you're having an evening of conversation in English. Nothing wrong with that, I suppose, but it is going to seem odd to those unfamiliar with that usage.