Should an Aviation include Crème de Violette?
According to wikipedia, the original Hugo Ensslin's recipe calls for 2 dashes of crème de violette.

In the same article there can be some variation on the theme, with or without crème de violette.

The Gin foundry website offers 2 recipes, with or without it; the version without the crème de violette dates from the 1930s and they say it might be because the product was hard to found at that time (ww2 era)

I'd say, if you want to be fully original, use the proper recipe with the crème de violette, but if you cannot find it, then it is not that big a deal as it is still historically correct.