No, not really, but given how there exist threads on Smogon by people who can't just get rid of a favorite to be able to beat Jirachi of all things, I wouldn't even be surprised if someone really wanted Gourgeist tested.
So here's the deal. An event has been announced that involves Supersize Pumpkaboo with a random ability - which includes Insomnia, its DW ability. This means there's now a way to get Supersize Gourgeist with Insomnia, whereas previously only the average-sized ones could, since those were the only ones that could be found in the Friend Safari. And considering that the bigger the better when it comes to Gourgeist, the buff provided here isn't nonexistent, as is the case with many events. Sure, it's not exactly a big buff either, but the ability to use arguably the best ability on the best size at least removes a source of frustration.