Registration is forever*. If you reserve a name, you have three years to use it in a registration. Generally, irises get introduced within a couple of years of being registered, but not always, especially for backyard hybridizers. Working in the database, I've seen some cases where there's a decade or so between registration and introduction.
*technically, names can be transferred from one iris to another, I can't remember all the requirements, but it's stuff like the no existing stock, can't have been used as a parent of a registered iris, etc.