You couldn't be more correct. For traditional Cajun dishes, the recipe has to come directly from the ancestors, in my humble opinion.
Okra can get a bit slimy so I understand why some people don't like it. I love fried okra but for me the presence of okra in gumbo neither enhances it nor detracts from the gumbo if it's not there. When I make gumbo I will put some okra in it if I happen to have some but if not I'm not going to run out and buy any. Okra is used as a thickener but I use file (I forgot how to put the accent mark ' over the text)
We only added okra to gumbo we mom made okra and shrimp gumbo. I dont remember how she made it but it was never slimy.
If I'm not mistaken, you turn the okra in the same time the trinity goes in after the roux is ready. You will get all the stringy goo then and you just keep turning till the okra wilts. Hit it with the stock after and you lose the slimy texture all together.
Tomatoes in your gumbo is a NOLA thing. And it's awesome. We put tomatoes in lots of things. Very large contingent of Sicilians down here in NOLA hence the muffaletta. You eventually get a blend of all the cultures and cuisines. Large Vietnamese population, too. Largest population of Hondurans in the USA as well.