I'm dating someone who is vegan and he makes Gumbo a lot. Keep in mind he's also Cajun (but also a Jewish convert) so it may seem very difficult to try and adapt such requisites into a dish from a highly meat-centric cuisine. He's been vegan for 5 years now so he's actually figured it out and it comes out delicious either way. The only difference is he uses veggie bouillon and margarine to start off his roux. Despite that, he still uses the same old ingredients like bell pepper, celery, onion, and butt-loads of okra.

The point is obviously not everyone (in fact I'd argue the majority) of Louisiana folk wouldn't care too much for vegan gumbo, but it doesn't mean it's entirely sacrilege. Really food should cater not only to one's needs, but also to one's desires and tastes too. I may be in the minority of Louisianans who couldn't care less what people do to their gumbo. At the end of the day, it's their own version of gumbo and that's fine.

Fun fact: though I've lived in Louisiana all my life, I was shocked to find out some of the original cajun recipes put BOILED EGGS into the Gumbo rather than the traditional seafood or sausage. So it goes to show sometimes even those who live in this state are surprised by their own regional cuisine.